import java.math.BigDecimal;
import java.util.*;

public class Main {

    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        long N = sc.nextLong();

        long ans = Long.MAX_VALUE;
        long rootN = (long)Math.sqrt(N);
        for (long i = 1; i <= rootN; i++) {
            long muti = N / i;
            if (N % i == 0) {
                ans = Math.min(ans, digit(muti));
            }
        }

        System.out.println(ans);
    }

    private static int digit(long n) {
        return String.valueOf(n).length();
    }
}
/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