import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int ans=0;
		for(int i=N ; i<=999 ; i++) {
			if(check(i)) {
				ans = i;
				break;
			}
		}
		System.out.println(ans);
		sc.close();
	}
	static boolean check(int n) {
		int one = n%10; n/=10;
		int two = n%10; n/=10;
		int thr = n%10;
		if( (one==two) && (two==thr) ) {
			return true;
		}
		return false;
	}

}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz