View Code of Problem 104

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNextInt()) {
            float n = scanner.nextInt()*1000;
            float v1 = scanner.nextInt();
            float v2 = scanner.nextInt();
            float t = scanner.nextInt();
            if (v1 - v2 <= 0) {
                System.out.println("NO");
            }else{
                float time = n/(v1-v2);
                if(time<=t) {
                    System.out.println(String.format("%.2f", time));
                }else {
                    System.out.println("NO");
                }
            }
        }
    }
}