import java.io.*;
import java.math.*;
import java.util.*;


public class Main {
	static int[] vy = {1,0,-1,0};
	static int[] vx = {0,1,0,-1};
	public static void main(String[] args) {	
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		long N = sc.nextInt();
		long G = sc.nextInt();
		long V = sc.nextInt();
		N /= 5;
		G *= N;
		
		System.out.printf("%.20f\n",G / (double)V);
	}
}