import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    long N = sc.nextLong();
    int ans = Integer.MAX_VALUE;
    for(long i = 1; i * i <= N; i++) {
      if(N % i == 0) {
        long b = N / i;
        int digit = 0;
        for(int j = 0; j <= 11; j++) {
          if(b < (long)Math.pow(10, j)) {
            digit = j;
            break;
          }
        }
        ans = Math.min(ans, digit);
      }
    }
    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