import numpy as np

def co_solve(n, a0, b0, a1, b1, a2, b2):
	r = 0
	for i, d in zip(range(a0), range(n, 0, -a1)):
		j = np.arange(0, min(a0, d // a2 + 1), dtype=np.uint64)
		v = np.amax(((d - j * a2) // a0) * b0 + i * b1 + j * b2)
		r = max(r, v)
	return r

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)