#include<iostream>
using namespace std;

int main()
{
	int n;
	int a[3][2],s[3];
	int i,m=100000;
	cin >> n;
	for (i = 0; i < 3; i++)
	{
		cin >> a[i][0] >> a[i][1];
		if (n % a[i][0] != 0)
		{
			s[i] = (n / a[i][0] + 1) * a[i][1];

		}
		else
		{
			s[i] = (n / a[i][0]) * a[i][1];
		}
		if (s[i] < m)
		{
			m = s[i];
		}
	}
	cout << m;
	return 0;

}