#include <iostream>
using namespace std;
int main() {
	int n, a, b, sum[4], min;
	cin >> n;
	for (int i = 1; i <= 3; i++) {
		cin >> a >> b;
		if (n % a == 0) sum[i] = (n / a) * b;
		else
			sum[i] = (n / a + 1) * b;
		}
	for (int i = 1; i <= 3; i++) {
		min = sum[1];
		if (sum[i] < min)
			min = sum[i];
	}
	cout << min;
	 return 0;
}