import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long min = Long.MAX_VALUE;
		long N = sc.nextLong();
		int max = (int) Math.sqrt(N);
		for (int i=1;i<=max;i++) {
			if (N%i==0) {
				long y = N/i;
				long temp = String.valueOf(y).length();
				if (temp <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