import java.util.*;

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

		long min = N + 1;
		for (int i = 2; i <= Math.sqrt(N); i++) {
			long temp = i + (N / i);
			if ((N % i == 0) && (temp < min)) {
				min = temp;
			}
		}
		System.out.println(min - 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