diff --git "a/Ukj0ng/202510/21 BOJ P5 \354\271\264\353\223\234 \352\262\214\354\236\204.md" "b/Ukj0ng/202510/21 BOJ P5 \354\271\264\353\223\234 \352\262\214\354\236\204.md"
new file mode 100644
index 00000000..606d6cf0
--- /dev/null
+++ "b/Ukj0ng/202510/21 BOJ P5 \354\271\264\353\223\234 \352\262\214\354\236\204.md"	
@@ -0,0 +1,70 @@
+```
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    private static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    private static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+    private static int[] uf, cards;
+    private static int N, M, K;
+    public static void main(String[] args) throws IOException {
+        init();
+
+        bw.flush();
+        bw.close();
+        br.close();
+    }
+
+    private static void init() throws IOException {
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+        K = Integer.parseInt(st.nextToken());
+
+        cards = new int[M];
+        uf = new int[M];
+
+        st = new StringTokenizer(br.readLine());
+
+        for (int i = 0; i < M; i++) {
+            cards[i] = Integer.parseInt(st.nextToken());
+            uf[i] = i;
+        }
+
+        Arrays.sort(cards);
+
+        st = new StringTokenizer(br.readLine());
+        for (int i = 0; i < K; i++) {
+            int input = Integer.parseInt(st.nextToken());
+            int temp = binarySearch(input);
+            int index = find(temp);
+
+            bw.write(cards[index] + "\n");
+            uf[index] = index + 1;
+        }
+    }
+
+    private static int binarySearch(int target) {
+        int left = 0;
+        int right = M-1;
+
+        while (left < right) {
+            int mid = left + (right - left) / 2;
+
+            if (target < cards[mid]) {
+                right = mid;
+            } else {
+                left = mid + 1;
+            }
+        }
+
+        return left;
+    }
+
+    private static int find(int x) {
+        if (uf[x] == x) return x;
+
+        return uf[x] = find(uf[x]);
+    }
+}
+```