import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;
import java.math.*;
 
public class Main {
	public static void main(String[] args)throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringBuilder sb = new StringBuilder();
		long n = Long.parseLong(br.readLine());
		int f = Integer.MAX_VALUE;
		for(long i = 100000; i > 0; i--){
			if(n%i==0){
				long a = n/i;
				f = Math.min(f,Math.max(String.valueOf(a).length(),String.valueOf(i).length()));
			}
		}
		System.out.println(f);
	}
}
/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