import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {

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

        final long n = sc.nextLong();

        List<Long> divisors = new ArrayList<>();

        int ans = Integer.MAX_VALUE;

        for (long i = 1; i * i <= n; i++) {
            if (n % i == 0) {
               final int f = Math.max(String.valueOf(i).length(), String.valueOf(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