import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        double tot = sc.nextDouble();
        if (tot <= 0) {
            System.out.println("Invalid input");
            return;   // only here we stop everything
        }

        // --- First calculation ---
        double iwr = sc.nextDouble();
        if (iwr <= 0) {
            System.out.println("-1");   // invalid, but continue
        } else {
            float first = (float)(tot / iwr);
            System.out.printf("%.1f%n", first);
        }

        // --- Second calculation ---
        double grp = sc.nextDouble();
        double gwr = sc.nextDouble();

        if (grp <= 0 || gwr <= 0) {
            System.out.println("-1");   // invalid, but don’t terminate
        } else {
            float second = (float)(tot / (grp * gwr));
            System.out.printf("%.1f%n", second);
        }
    }
}