import java.util.Scanner;
public class Main {
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		double n = scan.nextDouble();
		long a = (long)n-1;
		double d =Math.sqrt(n);
		for(long i=2; i<d+1; i++){
			double b = n/i;
			if(b == (long)b){
				a=(long)b+(long)i-2;
			}
		}
		System.out.println(a);   

	}
}
/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