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
    for j in range(a0):
      r = max(r, (d // a0) * b0 + i * b1 + j * b2)
      d -= a2
      if d < 0:
        break
  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())

  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),
0
  )
  print(result)

if __name__ == "__main__":
  main()