//丹阳新区实小路彦
#include <bits/stdc++.h>
using namespace std;
int n, w[10005], v[10005], ans[10005], j[10005], minn = INT_MAX;
int main()
{
cin >> n;
for (int i = 1; i <= 3; i++)
cin >> w[i] >> v[i];
for (int i = 1; i <= 3; i++)
{
ans[i] = n / w[i];
if (n % w[i] != 0) ans[i]++;
j[i] = ans[i] * v[i];
minn = min(minn, j[i]);
}
cout << minn << endl;
return 0;
}