input: Write a function to print the Fibonacci series up to a given number. The function should take an integer n as input and print the Fibonacci sequence up to the nth number. If n is less than 0, the function should print "Incorrect input". The function should return nothing.
  assert fibonacci(-1) == None
  assert fibonacci(0) == None
  assert fibonacci(5) == None
  assert fibonacci(10) == None
output: def fibonacci(n):
      if n < 0:
          print("Incorrect input")
          return
      a, b = 0, 1
      for _ in range(n):
          print(a, end=' ')
          a, b = b, a + b
      print()