import java.util.*;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        long min = 100;
        for(long i = 1; i * i <= n; i++) {
            if(n % i == 0) {
                long devider = n / i;
                long maxDigits = countMaxDigits(i, devider);
                min = Math.min(min, maxDigits);
            }
        }
        System.out.println(min);
    }

    static long countMaxDigits(long dev1, long dev2) {
        long count = 0;
        while(dev1 != 0 || dev2 != 0) {
            count++;
            dev1 /= 10;
            dev2 /= 10;
        }
        return count;
    }
}

/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