import java.util.Scanner;
public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		long seisu = scan.nextLong();
		long syou = 0;
		long a = 0,b = 0;
		long re = Long.MAX_VALUE;

		for(int i=1;i<=Math.sqrt(seisu);i++) {

			if(seisu%i==0) {
				a = i;
			b = seisu/i;
			}
		re = Math.min(re,a+b-2);
		}
		System.out.println(re);
		scan.close();

	}

}

/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