def co_solve(n, a0, b0, a1, b1, a2, b2):
	return max([
		max([
			(dj // a0) * b0 + i * b1 + j * b2
			for j, dj in zip(range(a0), range(di, 0, -a2))
		])
		for i, di in zip(range(a0), range(n, 0, -a1))
	])

n = int(input())
a0, b0 = (int(x) for x in input().split())
a1, b1 = (int(x) for x in input().split())
a2, b2 = (int(x) for x in input().split())

result = max(
	co_solve(n, a0, b0, a1, b1, a2, b2),
	co_solve(n, a1, b1, a2, b2, a0, b0),
	co_solve(n, a2, b2, a0, b0, a1, b1),
)

print(result)