input: Write a function to generate the first x Fibonacci numbers.
  assert fibonacci(5) == [1, 1, 2, 3, 5]
  assert fibonacci(10) == [1, 1, 2, 3, 5, 8, 13, 21, 34, 55]
  assert fibonacci(1) == [1]
output: def fibonacci(x):
      if x <= 0:
          return []
      elif x == 1:
          return [1]
      
      fib_sequence = [1, 1]
      while len(fib_sequence) < x:
          fib_sequence.append(fib_sequence[-1] + fib_sequence[-2])
      return fib_sequence