diff --git a/LeeTaeHo/boj/boj15817.java b/LeeTaeHo/boj/boj15817.java
new file mode 100644
index 00000000..f637adf8
--- /dev/null
+++ b/LeeTaeHo/boj/boj15817.java
@@ -0,0 +1,28 @@
+import java.io.*;
+import java.util.*;
+
+public class boj15817 {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        int n = Integer.parseInt(st.nextToken());
+        int x = Integer.parseInt(st.nextToken());
+        int[] pipe = new int[x + 1];
+        pipe[0] = 1;
+        for (int i = 0; i < n; i++) {
+            st = new StringTokenizer(br.readLine());
+            int length = Integer.parseInt(st.nextToken());
+            int cnt = Integer.parseInt(st.nextToken());
+            for (int j = x; j >= length; j--) {
+                for (int k = 1; k <= cnt; k++) {
+                    if(j - length * k >= 0){
+                        pipe[j] += pipe[j - length * k];
+                    }
+                }
+            }
+        }
+
+        System.out.println(pipe[x]);
+    }
+}
\ No newline at end of file
diff --git a/LeeTaeHo/boj/boj18427.java b/LeeTaeHo/boj/boj18427.java
new file mode 100644
index 00000000..0176f47e
--- /dev/null
+++ b/LeeTaeHo/boj/boj18427.java
@@ -0,0 +1,40 @@
+import java.io.*;
+import java.util.*;
+
+public class boj18427 {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        int n = Integer.parseInt(st.nextToken());
+        st.nextToken();
+        int h = Integer.parseInt(st.nextToken());
+
+        int[] dp = new int[h + 1];
+
+        List<Integer>[] block = new ArrayList[n + 1];
+
+        for (int i = 1; i <= n; i++) {
+            block[i] = new ArrayList<>();
+            st = new StringTokenizer(br.readLine());
+            while (st.hasMoreTokens()){
+                block[i].add(Integer.parseInt(st.nextToken()));
+            }
+        }
+
+        dp[0] = 1;
+
+        for (int i = 1; i <= n; i++) {
+            for (int j = h; j >= 0; j--) {
+                for (int k : block[i]) {
+                    if(j - k >= 0){
+                        dp[j] += dp[j - k];
+                        dp[j] %= 10007;
+                    }
+                }
+            }
+        }
+
+        System.out.println(dp[h]);
+    }
+}
diff --git a/LeeTaeHo/boj/boj2660.java b/LeeTaeHo/boj/boj2660.java
new file mode 100644
index 00000000..1d787cd7
--- /dev/null
+++ b/LeeTaeHo/boj/boj2660.java
@@ -0,0 +1,66 @@
+import java.io.*;
+import java.util.*;
+
+public class boj2660 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        int n = Integer.parseInt(br.readLine());
+        int[][] dp = new int[n + 1][n + 1];
+
+        for (int i = 1; i <= n; i++) {
+            Arrays.fill(dp[i], 100000000);
+            dp[i][i] = 0;
+        }
+
+        while (true) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            int p1 = Integer.parseInt(st.nextToken());
+            int p2 = Integer.parseInt(st.nextToken());
+
+            if (p1 == -1 && p2 == -1) break;
+
+            dp[p1][p2] = dp[p2][p1] = 1;
+        }
+
+        for (int k = 1; k <= n; k++) {
+            for (int i = 1; i <= n; i++) {
+                for (int j = 1; j <= n; j++) {
+                    if (dp[i][j] > dp[i][k] + dp[k][j]) {
+                        dp[i][j] = dp[i][k] + dp[k][j];
+                    }
+                }
+            }
+        }
+
+        int[] score = new int[n + 1];
+        int minValue = 100000000;
+
+        for (int i = 1; i <= n; i++) {
+            for (int j = 1; j <= n; j++) {
+                if (score[i] < dp[i][j]) {
+                    score[i] = dp[i][j];
+                }
+            }
+            if (minValue > score[i]) {
+                minValue = score[i];
+            }
+        }
+
+        StringBuilder sb = new StringBuilder();
+        int cnt = 0;
+        List<Integer> list = new ArrayList<>();
+        for (int i = 1; i <= n; i++) {
+            if (score[i] == minValue) {
+                cnt++;
+                list.add(i);
+            }
+        }
+
+        sb.append(minValue).append(" ").append(cnt).append("\n");
+        for (int i : list) {
+            sb.append(i).append(" ");
+        }
+
+        System.out.println(sb);
+    }
+}
\ No newline at end of file