import java.util.Scanner;

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

        long mini = N + 1;

        for (long i = 1; i*i <= N; i++) {
            if (N % i == 0) {
                long j = N/i;
                mini = Math.min(i+j, mini);
            }
        }
        System.out.println(mini - 2);
        s.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