import numpy as np

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