import java.util.ArrayList;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
       
        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        ArrayList<Long> list = new ArrayList<>();
        long ans1 = 0;
        long ans2 = 0;
        for(long i = 1; i * i <= a; i++){
            if(a % i == 0){
                list.add(i);
                list.add(a/i);
            }
        }
        ans1 = list.get(list.size() - 2) - 1;
        ans2 = list.get(list.size() - 1) - 1;
        System.out.println(ans1 + ans2);
    }
}
/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