import java.util.Scanner;
public class Main{
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		long N =sc.nextLong();
		long G =sc.nextLong();
		long V =sc.nextLong();
		int maisu=(int)N/5;
		long guramu=maisu * G;
		long noudo= guramu/V;
		System.out.println(noudo);
	}
}