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 = Long.MAX_VALUE;
        for(long i=1; i*i<=n; i++) {
            if(n % i == 0) {
                long digitsA = String.valueOf(i).length();
                long digitsB = String.valueOf(n/i).length();
                ans = Math.min(Math.max(digitsA,digitsB),ans);
            }
        }
        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