diff --git a/boj/solved/brute_force/2531/Main.java b/boj/solved/brute_force/2531/Main.java
new file mode 100644
index 0000000..d618210
--- /dev/null
+++ b/boj/solved/brute_force/2531/Main.java
@@ -0,0 +1,52 @@
+import java.io.*;
+import java.util.*;
+
+class Main {
+    static int n, d, k, c;
+    static int[] cycle;
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        n = Integer.parseInt(st.nextToken());
+        d = Integer.parseInt(st.nextToken());
+        k = Integer.parseInt(st.nextToken());
+        c = Integer.parseInt(st.nextToken());
+        
+        cycle = new int[n];
+        for(int i = 0;i<n;i++) {
+            cycle[i] = Integer.parseInt(br.readLine());
+        }
+
+        int[] sushi = new int[d+1];
+        int count = 0;
+        int res = 0;
+        for(int i = 0;i<k;i++) {
+            if (sushi[cycle[i]] == 0) {
+                count +=1;
+            }
+            sushi[cycle[i]] +=1;
+            res = Math.max(res, count);
+        }
+
+        for(int i = 0;i<n;i++) { // 앞에 초밥(i)을 빼고 뒤의 초밥(i+k)을 추가   
+            sushi[cycle[i]] -= 1;
+            if (sushi[cycle[i]] == 0) {
+                count -=1;
+            }
+
+            if (sushi[cycle[(i+k) % n]] == 0) {
+                count +=1;
+            }
+            sushi[cycle[(i+k) % n]] += 1;
+
+            if (sushi[c] == 0) {
+                res = Math.max(res, count + 1);
+            }
+            else {
+                res = Math.max(res, count);
+            }
+        }
+        
+        System.out.println(res);
+    }
+}
\ No newline at end of file