# ZeroJudge - f312: 1.人力分配
### 題目連結：https://zerojudge.tw/ShowProblem?problemid=f312
###### tags: `ZeroJudge` `窮舉` `數學`

#include <iostream>
#include <algorithm>
using namespace std;
#define SQUARE(x) (x * x)

int main() {
	cin.sync_with_stdio(false), cin.tie(nullptr);
	int A1, A2, B1, B2, C1, C2, employees, maximum = 1 << 31;
	cin >> A1 >> B1 >> C1 >> A2 >> B2 >> C2 >> employees;
	for (int i = 0; i <= employees; ++i)
		maximum = max(maximum, A1 * SQUARE(i) + B1 * i + C1 + A2 * SQUARE((employees - i)) + B2 * (employees - i) + C2);
	cout << maximum << '\n';
}