import java.util.*;
 
public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		long n = sc.nextLong();
		long a=0;
		boolean warikire = false;

		for(int i=2; i<=Math.sqrt(n); i++){
			if( n%i == 0 ){
				a = i;
				warikire = true;
			}
		}

		if(warikire){
			System.out.println( keta(n/a) );
		}else{
			System.out.println( keta(n) );
		}
		return;
	}

	public static int keta( long a ){
		int ans = 1;
		while( a/10 != 0 ){
			a /= 10;
			ans++;
		}
		return 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