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;
        if(n < 112) ans = 111;
        else if(n < 223) ans = 222;
        else if(n < 334) ans = 333;
        else if(n < 445) ans = 444;
        else if(n < 556) ans = 555;
        else if(n < 667) ans = 666;
        else if(n < 778) ans = 777;
        else if(n < 889) ans = 888;
        else ans = 999;
        System.out.println(ans);
    }
}
/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