import java.io.IOException;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) throws IOException {
		Scanner scanner = new Scanner(System.in);
		long n = scanner.nextLong();
		int ans = 0;
		long a = 0;
		long i;
		long j = 0;
		for(i = 1; i*i <= n; i++){
			if(n % i == 0){
				a = (int) (n / i);
				j = i;
			}
		}
		int p = String.valueOf(a).length();
		int q = String.valueOf(j).length();
		if(p < q){
			System.out.println(q);
		}else{
			System.out.println(p);
		}
	}
}
/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