#include"iostream"
#include"cstring"
#include"cmath"
using namespace std;
int main()
{
	int n;
	cin >> n;
	int sum=0x3f3f3f;
		for (int i = 0; i < 3; i++)
		{
			int qian, shu;
			cin >> shu >> qian;
			sum = min(sum, (int)ceil((n * 1.0) / shu) * qian);
		}
		cout << sum;
	return 0;
}