import java.util.Arrays;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Scanner;
import java.util.Set;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		final long N = sc.nextLong();
		final long G = sc.nextLong();
		final long V = sc.nextLong();
		
		System.out.printf("%.14f\n", (N / 5) * G / (double)(V));
	}

}