import java.io.*;
import java.util.*;
class Program{
    int solve(int i, int size){
        int temp = i;
        for(int j=1;j<size;j++){
            temp=temp*10+i;
        }
        return temp;
    }
}
class Main{
    public static void main(String[] args) {
        Program obj = new Program();
        Scanner in = new Scanner(System.in);
        int N = in.nextInt();
        for(int i=1;i<=9;i++){
            if(obj.solve(i,String.valueOf(N).length())>=N) {System.out.println(obj.solve(i,String.valueOf(N).length())); break;}
            //System.out.println(obj.solve(i,String.valueOf(N).length()));
        }
    }
}
/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