import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		Long N = sc.nextLong();
      
        int sq = (int) Math.floor(Math.sqrt((double)N));
      	for(int i = sq; i > 0; i--){
          	if(N%i==0){
              if(i>(N/i)){
                System.out.println(String.valueOf(i).length());
                return;
              }else{
                Long ans = (long) (N/i);
                System.out.println(String.valueOf(ans).length());
                return;
              }
            }
        }
		System.out.println(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