
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        long n = sc.nextLong();
        long ans = 1L << 60;

        for (long i = 1; i * i <= n; i++) {
            if (n % i == 0) {
                int f = Math.max(("" + i).length(), ("" + (n / i)).length());
                ans = Math.min(ans, f);
            }
        }

        System.out.println(ans);
    }
}

/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