import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    long n = Long.parseLong(sc.next());
    long ans = n - 1;
    long a, b;
    for(int i = 1; i <= Math.sqrt(n); i++) {
      if(n % i == 0) {
        a = i;
        b = n / i;
        ans = Math.min(ans, a + b - 2);
      }
    }
    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