import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        double g = sc.nextInt();
        int v = sc.nextInt();
        double ans = n / 5 * g / v;
        System.out.println(new java.math.BigDecimal(ans).toPlainString());
    }
}