package yukicoder;
import java.util.Scanner;
public class Main {
	public static void main(String[] args){
		new Main().solver();
	}
	void solver(){
		Scanner sc=new Scanner(System.in);
		int N=sc.nextInt();
		int G=sc.nextInt();
		int V=sc.nextInt();
		
		System.out.println((double)(N/5)*(double)G/((double)V));
		
	}
}