#include<iostream>
using namespace std;
int main()
{
	long n, arr[3][2];
	long min = 21000000000000;
	cin >> n;
	for (int i = 0; i < 3; i++)//输入
	{
		for (int j = 0; j < 2; j++)
		{
			cin >> arr[i][j];
		}
	}
	for (int k = 0; k < 3; k++)//逐个比较
	{
		long temp;
		if (n % arr[k][1] == 0)
		{
			temp = n / arr[k][1] * arr[k][2];
		}
		else if (n%arr[k][1] != 0)
		{
			temp = (n / arr[k][1] + 1) * arr[k][2];
		}
		if (temp < min)
		{
			min = temp;
		}//如果temp值小于min值就将min赋值为temp
	}
	cout << min << endl;
	system("pause");
	return 0;
}