import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long n = sc.nextLong();
		sc.close();
		long r = Long.MAX_VALUE;
		// min(i,j)<=nのルート<=10^6
		for(long i=1; i*i<=n; i++) {
			if(n%i != 0) continue;
			long j = n/i;
			r = Math.min(r, i+j-2);
		}
		System.out.println(r);
	}
}
/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