

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		long N = sc.nextLong();

		long last = 0;

		long i = 1;
		long sqrt_N = (long)Math.sqrt(N);
		while(i <= sqrt_N){
			if(N % i == 0){
				last = N / i;
			}
			i++;
		}

		System.out.println(String.valueOf(last).length());

		sc.close();
	}

}

/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