#include<iostream>
using namespace std;
struct pencil
{
	int num;
	int price;
	int sum;
};
int main()
{
	int a,b;
	cin >> a;
	pencil arr1[3];
	for (int i = 0; i < 3; i++)
	{
		cin >> arr1[i].num >> arr1[i].price;
	}
	for (int i = 0; i < 3; i++)
	{
		if (a / arr1[i].num == 0)
		{
			arr1[i].sum = arr1[i].price * (a / arr1[i].num);
		}
		else
		{
			arr1[i].sum = arr1[i].price * (a / arr1[i].num + 1);
		}
	}
	for (int i = 0; i < 2; i++)
	{
		for (int j = 0; j < 2 - i; j++)
		{
			if (arr1[j].sum > arr1[j + 1].sum)
			{
				int temp = arr1[j].sum;
				arr1[j].sum = arr1[j + 1].sum;
				arr1[j + 1].sum = temp;
			}
		}
	}
	cout << arr1[0].sum << endl;
	system("pause");
	return 0;
}