import java.util.*;

public class Main {
	private static Scanner sc = new Scanner(System.in);
	public static void main(String[] args) {
		long n = sc.nextLong();
		long ret = Long.MAX_VALUE;
		for (int i = 1;i <= Math.sqrt(n);i++) {
			if (n%i==0) {
				int l1 = String.valueOf(i).length();
				int l2 = String.valueOf(n/i).length();
				ret = Math.min(ret, Math.max(l1, l2));
			}
		}
		System.out.println(ret);
	}
}
/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