import java.util.Scanner;

public class Main {

  public static void main(String[] args) {

    Scanner scan = new Scanner(System.in);

    long n = scan.nextLong();

    long start = (long) Math.sqrt(n);
    
    for (long i = start; i >= 1; i--) {
      if (n % i == 0) {
        String str = Long.toString(Math.max(i, n / i));
        System.out.println(str.length());
        return;
      }
    }

  }

}
/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