import java.util.Scanner;
class YukiCoder02 {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long N =sc.nextLong();
		long G =sc.nextLong();
		long V =sc.nextLong();
		long m = N / 5;
		long k = m*G;
		long n =k/V;

		System.out.println(n);

	}

}