import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    long n = sc.nextLong();
    int ans = String.valueOf(n).length();
    
    for (long i = 1; i * i <= n; i++) {
      final int length = String.valueOf(n / i).length();
      if (n % i == 0 && length < ans) {
        ans = length;
      }
    }
    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