import java.util.*;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String n = String.valueOf(sc.nextInt());
		String rn = "",rs = "";
		char n1 = n.charAt(0),n2 = n.charAt(1),n3 = n.charAt(2);
		if(n1 == n2 && n2 == n3) {
			System.out.println(Integer.valueOf(n));
			return;
		}else if(n1 == n2){
			if((int)n2 > (int)n3) {
				rs = String.valueOf(n1);
			}else {
				 rs = String.valueOf((char)((int)n1 + 1));
			}
		}else {
			if((int)n1 > (int)n2) {
				rs = String.valueOf(n1);
			}else {
				rs = String.valueOf((char)((int)n1 + 1));
			}
		}
		rn += rs+rs+rs;
		System.out.println(rn);
	}
}
/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