import java.io.*;
import java.util.*;
import java.lang.*;
import static java.lang.System.*;
public class Main
{
public static void  main (String args[])throws Exception
{
Scanner sc=new Scanner(in);
long n=sc.nextLong();
int ans=10000;
for(int i=1;i<=(int)(Math.sqrt(n))+2;i++)
{
	if(n%i==0)
	{
		String a=String.valueOf(i);
		String b=String.valueOf(n/i);
		int c=Math.max(a.length(),b.length());
		if(c<=ans)
		ans=c;

	}
}
out.println(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