diff --git "a/ksh/week3/\354\212\244\355\203\235_\354\210\230\354\227\264.java" "b/ksh/week3/\354\212\244\355\203\235_\354\210\230\354\227\264.java"
new file mode 100644
index 0000000..7999b82
--- /dev/null
+++ "b/ksh/week3/\354\212\244\355\203\235_\354\210\230\354\227\264.java"
@@ -0,0 +1,34 @@
+package week3;
+
+import java.io.*;
+import java.util.Stack;
+
+public class 스택_수열 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        Stack<Integer> stack = new Stack<>();
+
+        int n = Integer.parseInt(br.readLine());
+        int[] arr = new int[n];
+        for (int i = 0; i < n; i++) {
+            arr[i] = Integer.parseInt(br.readLine());
+        }
+
+        StringBuilder sb = new StringBuilder();
+
+        int count = 1;
+        for (int num : arr) {
+            while (stack.empty() || stack.peek() < num) {
+                stack.push(count++);
+                sb.append("+\n");
+            }
+            if (stack.peek() != num) {
+                System.out.println("NO");
+                return;
+            }
+            stack.pop();
+            sb.append("-\n");
+        }
+        System.out.println(sb);
+    }
+}
\ No newline at end of file
diff --git "a/ksh/week3/\354\230\244\355\201\260\354\210\230.java" "b/ksh/week3/\354\230\244\355\201\260\354\210\230.java"
new file mode 100644
index 0000000..c606600
--- /dev/null
+++ "b/ksh/week3/\354\230\244\355\201\260\354\210\230.java"
@@ -0,0 +1,37 @@
+package week3;
+
+import java.io.*;
+import java.util.Stack;
+import java.util.StringTokenizer;
+
+public class 오큰수 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+        Stack<Integer> stack = new Stack<>();
+
+        int n = Integer.parseInt(br.readLine());
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        int[] arr = new int[n];
+        for (int i = 0; i < n; i++) {
+            arr[i] = Integer.parseInt(st.nextToken());
+        }
+
+        for (int i = 0; i < n; i++) {
+            while (!stack.empty() && arr[stack.peek()] < arr[i]) {
+                arr[stack.pop()] = arr[i];
+            }
+            stack.push(i);
+        }
+
+        while (!stack.empty()) {
+            arr[stack.pop()] = -1;
+        }
+
+
+        for (int num : arr) {
+            bw.write(num + " ");
+        }
+        bw.close();
+    }
+}