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
    r1 = i * b1
    for j in range(min(a0, d // a2 + 1)):
      r = max(r, ((d - j * a2) // a0) * b0 + r1 + j * b2)
  return r

def main():
  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())

  r1 = co_solve(n, a0, b0, a1, b1, a2, b2)
  r2 = co_solve(n, a1, b1, a2, b2, a0, b0)
  r3 = co_solve(n, a2, b2, a0, b0, a1, b1)
  result = max((r1, r2, r3))
  print(result)

if __name__ == "__main__":
  main()