diff --git "a/lkhyun/202509/11 BOJ G4 \352\263\240\354\270\265 \352\261\264\353\254\274.md" "b/lkhyun/202509/11 BOJ G4 \352\263\240\354\270\265 \352\261\264\353\254\274.md"
new file mode 100644
index 00000000..2435bc43
--- /dev/null
+++ "b/lkhyun/202509/11 BOJ G4 \352\263\240\354\270\265 \352\261\264\353\254\274.md"	
@@ -0,0 +1,47 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+    static StringTokenizer st;
+    static int N;
+    static int[] buildings;
+    static int[] cnt;
+    static int max;
+    
+    public static void main(String[] args) throws IOException {
+        N = Integer.parseInt(br.readLine());
+        buildings = new int[N+1];
+        cnt = new int[N+1];
+
+        st = new StringTokenizer(br.readLine());
+        for (int i = 1; i <= N; i++) {
+            buildings[i] = Integer.parseInt(st.nextToken());
+        }
+
+        for (int i = 1; i < N; i++) {
+            for (int j = i+1; j <= N; j++) {
+                double slope = (double)(buildings[j]-buildings[i]) / (j-i);
+                boolean isPossible = true;
+                for (int k = 1; i+k < j; k++) {
+                    if(buildings[i]+(slope*k) <= buildings[i+k]){
+                        isPossible = false;
+                        break;
+                    }
+                }
+                if(isPossible){
+                    cnt[i]++;
+                    cnt[j]++;
+                }
+            }
+        }
+        for (int i = 1; i <= N; i++) {
+            max = Math.max(cnt[i], max);
+        }
+        bw.write(max+"");
+        bw.close();
+    }
+}
+```