#include<bits/stdc++.h>
#include<cmath>
using namespace std;
#define DBL_MAX 1.7976931348623158e+308
int main()
{
	double n, s, m = DBL_MAX;
	cin >> n;
	double  a[3], b[3];
	for (int i = 0; i < 3; i++)
	{
		cin >> a[i] >> b[i];
		s = ceil(n / a[i]);
		if (s * b[i] <= m) {
			m = s * b[i];
		}
	}
 printf("%.0lf\n", m);
	return 0;
}