import numpy as np
n = int(input())
ab = [list(map(int, input().split())) for _ in range(3)] * 2
print(
	max(
		max(
			np.amax(((d - j * ar) // ap) * bp + i * bq + j * br)
			for i, j, d in zip(
				range(ap),
				map(lambda d: np.arange(0, min(ap, d // ar + 1), dtype=np.uint64), range(n, 0, -aq)),
				range(n, 0, -aq),
			)
		)
		for [[ap, bp], [aq, bq], [ar, br]] in [ab[0:3], ab[1:4], ab[2:5]]
	)
)