import java.util.Scanner;

public class N379 {
	public static void main(String[] args)
	{
		Scanner sc=new Scanner(System.in);
		long N=sc.nextLong();double G=sc.nextDouble(),V=sc.nextDouble();
		N=N/5;
		G=G/V;
		double ans=N*G;
		System.out.printf("%.13f",ans);
}}