import java.util.*;
import java.io.*;

class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        long tmp = N+1;
        long ans = 0;

        for(long i = 1; i < Math.sqrt(N)+1; i++){
            if(N % i == 0){
                ans = N / i;
                tmp = Math.min(tmp,ans+i);
            }
        }

        /*for(long i = 1; i < (N/2); i++){
            if(N % i == 0){
                ans2 = N / i;
                //ans2 = (int)ans;
                tmp = Math.min(tmp,ans2+i);
            }
        }*/

        System.out.println(tmp - 2);
    }
}
/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