import java.util.Scanner;
import java.util.Arrays;
import java.math.BigDecimal;

public class a{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
		int a=sc.nextInt();
		int b=sc.nextInt();
		int c=sc.nextInt();
		
		int node;
		
		node = ((a/5) * b)/c;
		
		System.out.println(node);
    }
}