import java.util.Scanner;
import java.util.HashSet;
import java.util.Set;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long N = sc.nextLong();

		Set<Long> x = new HashSet<>();
		
		for(long i = 1; i * i <= N; i++) {
			if(N % i == 0) {
				x.add(i);
				x.add(N / i);
			}
		}
		
		int min = 100;
		
		for(Long i : x) {
			String a = String.valueOf(i);
			String b = String.valueOf(N / i);
			int temp = Math.max(a.length(), b.length());
			min = Math.min(min, temp);
		}
		System.out.println(min);
	}
}

/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