import java.util.*;

public class Main {
	
	public static void main(String[] args)  {
		Scanner scan = new Scanner(System.in);
		long n=Long.parseLong(scan.next());
		
		long ans=1000000000000L;
		for (long i=1;i*i<=n;++i) {
			if (n%i!=0)continue;			
			ans=Math.min(ans, i+n/i-2);			
		}
		
		System.out.print(ans);
		
		
}		
}
//end
/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