import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc=new Scanner(System.in);
        long n=Long.parseLong(sc.next());
        sc.close();
        for(long a=(long) Math.sqrt(n);a>=1;a--){
            if(n%a==0){
                long b=n/a;
                String b_str=Long.toString(b);
                System.out.println(b_str.length());
                System.exit(0);
            }
        }
    }
}
/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