import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long n = Long.parseLong(sc.next());
		int min = Integer.MAX_VALUE;
		for (long a = 1; a <= Math.sqrt(n); a++) {
			if (n % a != 0)
				continue;
			int l = String.valueOf(n / a).length();
			if (l < min)
				min = l;
		}
		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