diff --git a/kangdy25/BOJ/1010.cpp b/kangdy25/BOJ/1010.cpp
new file mode 100644
index 000000000..779042235
--- /dev/null
+++ b/kangdy25/BOJ/1010.cpp
@@ -0,0 +1,24 @@
+// 다리 놓기 / 실버 5
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    int N, K, result = 1;
+    cin >> N >> K;
+    int NK = N - K;
+
+    for (int i = N; i >= 1; i--) {
+        result *= i;
+    }
+    for (int j = K; j >= 1; j--) {
+        result /= j;
+    }
+    for (int j = NK; j >= 1; j--) {
+        result /= j;
+    }
+    cout << result << "\n";
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/10773.cpp b/kangdy25/BOJ/10773.cpp
new file mode 100644
index 000000000..28662b576
--- /dev/null
+++ b/kangdy25/BOJ/10773.cpp
@@ -0,0 +1,29 @@
+// 제로 / 실버 4
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    int K, num, total = 0;
+    cin >> K;
+    stack<int> money;
+
+    while (K--) {
+        cin >> num;
+        if (num == 0) {
+            money.pop();
+        }
+        else {
+            money.push(num);
+        }
+    }
+
+    while (!money.empty()) {
+        total += money.top();
+        money.pop();
+    }
+    cout << total << "\n";
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/10870.cpp b/kangdy25/BOJ/10870.cpp
new file mode 100644
index 000000000..45e6cdc52
--- /dev/null
+++ b/kangdy25/BOJ/10870.cpp
@@ -0,0 +1,24 @@
+// 피보나치 수 5 / 브론즈 2
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int Fibonacci(int n) {
+    if (n == 0) {
+        return 0;
+    } else if (n == 1) {
+        return 1;
+    } else {
+        return Fibonacci(n - 2) + Fibonacci(n - 1);
+    }
+}
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    
+    int N;
+    cin >> N;
+    
+    cout << Fibonacci(N) << "\n";
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/10872.cpp b/kangdy25/BOJ/10872.cpp
new file mode 100644
index 000000000..516a921d1
--- /dev/null
+++ b/kangdy25/BOJ/10872.cpp
@@ -0,0 +1,15 @@
+// 팩토리얼 / 브론즈 3
+#include <iostream>
+using namespace std;
+
+int factorial(int n) {
+    if (n == 0) return 1;
+    else return n * factorial(n - 1);
+}
+
+int main() {
+    int N;
+    cin >> N;
+    cout << factorial(N);
+    return 0;
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/11050.cpp b/kangdy25/BOJ/11050.cpp
new file mode 100644
index 000000000..90e022c33
--- /dev/null
+++ b/kangdy25/BOJ/11050.cpp
@@ -0,0 +1,25 @@
+// 이항 계수 1 / 브론즈 1
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    int N, K, result = 1;
+    cin >> N >> K;
+    int NK = N - K; 
+    
+
+    for (int i = N; i >= 1; i--) {
+        result *= i;
+    }
+    for (int j = K; j >= 1; j--) {
+        result /= j;
+    }
+    for (int j = NK; j >= 1; j--) {
+        result /= j;
+    }
+    cout << result << "\n";
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/11866.cpp b/kangdy25/BOJ/11866.cpp
new file mode 100644
index 000000000..6dda15e88
--- /dev/null
+++ b/kangdy25/BOJ/11866.cpp
@@ -0,0 +1,31 @@
+// 요세푸스 문제 0 / 실버 5
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    
+    int N, K;
+    cin >> N >> K;
+    queue<int> q;
+    
+    for (int i = 1; i <= N; i++) {
+        q.push(i);
+    }
+    
+    cout << "<";
+    while (!q.empty()) {
+        for (int i = 1; i < K; i++) {
+            q.push(q.front());
+            q.pop();
+        }
+        cout << q.front(); 
+        if (q.size() > 1) {
+            cout << ", ";
+        }
+        q.pop();
+    }
+    cout << ">";
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/12789.cpp b/kangdy25/BOJ/12789.cpp
new file mode 100644
index 000000000..84bd25da7
--- /dev/null
+++ b/kangdy25/BOJ/12789.cpp
@@ -0,0 +1,32 @@
+// 도키도키 간식드리미 / 실버 3
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    int N, num, cnt = 1;
+    cin >> N;
+    stack<int> st;
+
+    for (int i = 0; i < N; i++) {
+        cin >> num;
+        if (num == cnt) {
+            cnt++;
+        } else {
+            st.push(num);
+        }
+
+        while(!st.empty() && st.top() == cnt) {
+            st.pop();
+            cnt++;
+        }
+    }
+    if (st.empty()) {
+        cout << "Nice\n";
+    } else {
+        cout << "Sad\n";
+    }
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/15439.cpp b/kangdy25/BOJ/15439.cpp
new file mode 100644
index 000000000..778c32c64
--- /dev/null
+++ b/kangdy25/BOJ/15439.cpp
@@ -0,0 +1,13 @@
+// 베라의 패션 / 브론즈 4
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    
+    int N;
+    cin >> N;
+    
+    cout << N * (N - 1);
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/18258.cpp b/kangdy25/BOJ/18258.cpp
new file mode 100644
index 000000000..2eec5cc6a
--- /dev/null
+++ b/kangdy25/BOJ/18258.cpp
@@ -0,0 +1,49 @@
+// 큐 2 / 실버 4
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    
+    int N, num;
+    string s;
+    queue<int> q;
+    cin >> N;
+    
+    while(N--) {
+        cin >> s;
+        if (s == "push") {
+            cin >> num;
+            q.push(num);
+        } else if (s == "pop") {
+            if (!q.empty()) {
+                cout << q.front() << "\n";
+                q.pop();
+            } else {
+                cout << "-1\n";
+            }
+        } else if (s == "size") {
+            cout << q.size() << "\n";
+        } else if (s == "empty") {
+            if (q.empty()) {
+                cout << "1\n";
+            } else {
+                cout << "0\n";
+            }
+        } else if (s == "front") {
+            if (q.empty()) {
+                cout << "-1\n";
+            } else {
+                cout << q.front() << "\n";
+            }
+        } else if (s == "back") {
+            if (q.empty()) {
+                cout << "-1\n";
+            } else {
+                cout << q.back() << "\n";
+            }
+        }    
+    }
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/2164.cpp b/kangdy25/BOJ/2164.cpp
new file mode 100644
index 000000000..bdf0811c9
--- /dev/null
+++ b/kangdy25/BOJ/2164.cpp
@@ -0,0 +1,34 @@
+// 카드2 / 실버 4
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    
+    int N;
+    cin >> N;
+    queue<int> q;
+    bool check = true;
+    
+    for (int i = 1; i <= N; i++) {
+        q.push(i);
+    }
+    if (N == 1) {
+        cout << "1\n";
+    } else {
+        while(q.size() != 1) {
+            if (check) {
+                q.pop();
+                check = false;
+            } else {
+                q.push(q.front());
+                q.pop();
+                check = true;
+            }
+            N--;
+        }
+        cout << q.back() << "\n";
+    }
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/2346.cpp b/kangdy25/BOJ/2346.cpp
new file mode 100644
index 000000000..7f235e617
--- /dev/null
+++ b/kangdy25/BOJ/2346.cpp
@@ -0,0 +1,39 @@
+// 풍선 터뜨리기 / 실버 3
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    int N, pop, coord, popTargetValue, popTargetCoord;
+    cin >> N;
+    deque<pair<int, int>> dq;
+
+    for (int i = 1; i <= N; i++) {
+        cin >> coord;
+        dq.push_back(make_pair(coord, i));
+    }
+
+    while (!dq.empty()) {
+        popTargetCoord = dq.front().first;
+        popTargetValue = dq.front().second;
+
+        cout << popTargetValue << " ";
+        dq.pop_front();
+
+        if (!dq.empty() && popTargetCoord > 0) {
+            for (int i = 1; i < popTargetCoord; i++) {
+                dq.push_back(dq.front());
+                dq.pop_front();
+            }
+        }
+        else if (!dq.empty() && popTargetCoord < 0) {
+            for (int i = 1; i < popTargetCoord * (-1) + 1; i++) {
+                dq.push_front(dq.back());
+                dq.pop_back();
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/24511.cpp b/kangdy25/BOJ/24511.cpp
new file mode 100644
index 000000000..cf71a16fd
--- /dev/null
+++ b/kangdy25/BOJ/24511.cpp
@@ -0,0 +1,35 @@
+// queuestack / 실버 3
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int N, M, check, queuestack[100001];
+deque<int> dq;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    
+    cin >> N;
+    for (int i = 0; i < N; i++) {
+        cin >> check;
+        queuestack[i] = check;
+    }
+    for (int i = 0; i < N; i++) {
+        int x;
+        cin >> x;
+        if (queuestack[i] == 0) {
+            dq.push_back(x);
+        }
+    }
+    
+    cin >> M;
+    for (int i = 0; i < M; i++) {
+        int x;
+        cin >> x;
+        dq.push_front(x);
+        cout << dq.back() << " ";
+        dq.pop_back();
+    }
+    
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/24723.cpp b/kangdy25/BOJ/24723.cpp
new file mode 100644
index 000000000..add0d18cd
--- /dev/null
+++ b/kangdy25/BOJ/24723.cpp
@@ -0,0 +1,16 @@
+// 녹색거탑 / 브론즈 4
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    
+    int N, result = 1;
+    cin >> N;
+    
+    for (int i = 1; i <= N; i++) {
+        result *= 2;
+    }
+    cout << result << "\n";
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/25501.cpp b/kangdy25/BOJ/25501.cpp
new file mode 100644
index 000000000..4b61db596
--- /dev/null
+++ b/kangdy25/BOJ/25501.cpp
@@ -0,0 +1,38 @@
+// 재귀의 귀재 / 브론즈 2
+#include <bits/stdc++.h>
+using namespace std;
+
+int cnt = 0;
+
+int recursion(const char* s, int l, int r) {
+    cnt++;
+    if (l >= r) {
+        return 1;
+    }
+    else if (s[l] != s[r]) {
+        return 0;
+    }
+    else {
+        return recursion(s, l + 1, r - 1);
+    }
+}
+
+int isPalindrome(const char* s) {
+    return recursion(s, 0, strlen(s) - 1);
+}
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    int T;
+    string S;
+    cin >> T;
+
+    for (int i = 0; i < T; i++) {
+        cnt = 0;
+        cin >> S;
+        cout << isPalindrome(S.c_str()) << " " << cnt << "\n";
+    }
+
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/27433.cpp b/kangdy25/BOJ/27433.cpp
new file mode 100644
index 000000000..00e2c7865
--- /dev/null
+++ b/kangdy25/BOJ/27433.cpp
@@ -0,0 +1,22 @@
+// 팩토리얼 2 / 브론즈 5 
+
+#include <bits/stdc++.h>
+using namespace std;
+
+long long Factorial(long long a) {
+    if (a == 0 || a == 1) {
+        return 1;
+    } else {
+        return a * Factorial(a-1);
+    }
+}
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    
+    long long N;
+    cin >> N;
+    
+    cout << Factorial(N) << "\n";
+}
diff --git a/kangdy25/BOJ/28278.cpp b/kangdy25/BOJ/28278.cpp
new file mode 100644
index 000000000..9eeeec53d
--- /dev/null
+++ b/kangdy25/BOJ/28278.cpp
@@ -0,0 +1,50 @@
+// 스택 2 / 실버 4
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    
+    int N, cmd, x;
+    cin >> N;
+    stack<int> s;
+    
+    while(N--) {
+        cin >> cmd;
+        switch (cmd) {
+            case 1:
+                cin >> x;
+                s.push(x);
+                break;
+            case 2:
+                if (s.empty()) {
+                    cout << "-1\n";
+                } else {
+                    cout << s.top() << "\n";
+                    s.pop();
+                }
+                break;
+            case 3:
+                cout << s.size() << "\n";
+                break;
+            case 4:
+                if (s.empty()) {
+                    cout << "1\n";
+                } else {
+                    cout << "0\n";
+                }
+                break;
+            case 5:
+                if (s.empty()) {
+                    cout << "-1\n";
+                } else {
+                    cout << s.top() << "\n";
+                }
+                break;
+            default: // do nothing
+                break; 
+        }
+    }
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/28279.cpp b/kangdy25/BOJ/28279.cpp
new file mode 100644
index 000000000..3ec790e13
--- /dev/null
+++ b/kangdy25/BOJ/28279.cpp
@@ -0,0 +1,69 @@
+// 덱 2 / 실버 4
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    
+    int N, cmd, num;
+    cin >> N;
+    deque<int> dq;
+    
+    while(N--) {
+        cin >> cmd;
+        switch (cmd) {
+            case 1:
+                cin >> num;
+                dq.push_front(num);
+                break;
+            case 2:
+                cin >> num;
+                dq.push_back(num);
+                break;
+            case 3:
+                if (!dq.empty()) {
+                    cout << dq.front() << "\n";
+                    dq.pop_front();
+                } else {
+                    cout << "-1\n";
+                }
+                break;
+            case 4:
+                if (!dq.empty()) {
+                    cout << dq.back() << "\n";
+                    dq.pop_back();
+                } else {
+                    cout << "-1\n";
+                }
+                break;
+            case 5:
+                cout << dq.size() << "\n";
+                break;
+            case 6:
+                if (!dq.empty()) {
+                    cout << "0\n";
+                } else {
+                    cout << "1\n";
+                }
+                break;
+            case 7:
+                if (!dq.empty()) {
+                    cout << dq.front() << "\n";
+                } else {
+                    cout << "-1\n";
+                }
+                break;
+            case 8:
+                if (!dq.empty()) {
+                    cout << dq.back() << "\n";
+                } else {
+                    cout << "-1\n";
+                }
+                break;
+            default:
+                break;
+        }
+    }
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/4949.cpp b/kangdy25/BOJ/4949.cpp
new file mode 100644
index 000000000..289992ebd
--- /dev/null
+++ b/kangdy25/BOJ/4949.cpp
@@ -0,0 +1,55 @@
+// 균형잡힌 세상 / 실버 4
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    string s = "";
+
+    while (true) {
+        bool check = true;
+        getline(cin, s);
+        stack<char> st;
+
+        if (s[0] == '.') {
+            break;
+        }
+
+        for (int i = 0; i < s.size(); i++) {
+            if (s[i] == '[' || s[i] == '(') {
+                st.push(s[i]);
+            }
+            else if (s[i] == ']') {
+                if (!st.empty() && st.top() == '[') {
+                    st.pop();
+                }
+                else {
+                    cout << "no\n";
+                    check = false;
+                    break;
+                }
+            }
+            else if (s[i] == ')') {
+                if (!st.empty() && st.top() == '(') {
+                    st.pop();
+                }
+                else {
+                    cout << "no\n";
+                    check = false;
+                    break;
+                }
+            }
+        }
+        if (check) {
+            if (st.empty()) {
+                cout << "yes\n";
+            }
+            else {
+                cout << "no\n";
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/kangdy25/BOJ/9012.cpp b/kangdy25/BOJ/9012.cpp
new file mode 100644
index 000000000..94567f460
--- /dev/null
+++ b/kangdy25/BOJ/9012.cpp
@@ -0,0 +1,43 @@
+// 괄호 / 실버 4
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    int N;
+    cin >> N;
+    string s;
+
+    while (N--) {
+        bool check = true;
+        cin >> s;
+        stack<int> st;
+        for (int i = 0; i < s.size(); i++) {
+            if (s[i] == '(') {
+                st.push(s[i]);
+            }
+            else {
+                if (!st.empty() && st.top() == '(') {
+                    st.pop();
+                }
+                else {
+                    cout << "NO\n";
+                    check = false;
+                    break;
+                }
+            }
+        }
+        if (check) {
+            if (st.empty()) {
+                cout << "YES\n";
+            }
+            else {
+                cout << "NO\n";
+            }
+
+        }
+    }
+}
\ No newline at end of file