import java.util.*;
public class Main{
	public static void main(String[] args){
    	Scanner sc = new Scanner(System.in);
      long n = sc.nextLong();
      long x = 0;
      for(long i = (long)Math.sqrt(n);i > 0;i--){
      	if(n%i==0){
        	x = n/i;
          break;
        }
      }
      System.out.println(String.valueOf(x).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