input: Write a function to print the Fibonacci series up to a given number 'n'. If the given number 'n' is less than 0, print "Incorrect input".
  def fibonacci(n): 
      a = 0
      b = 1
      series = []
      if n < 0: 
          print("Incorrect input") 
      else: 
          series.append(a)
          if n > 0:
              series.append(b)
          for i in range(2, n+1): 
              c = a + b 
              a = b 
              b = c 
              series.append(b)
          print(series)
  
  assert fibonacci(5)==[0, 1, 1, 2, 3, 5]
  assert fibonacci(-1)=="Incorrect input"
  assert fibonacci(0)==[0]
  assert fibonacci(1)==[0, 1]
  assert fibonacci(10)==[0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]
output: def fibonacci(n): 
      a = 0
      b = 1
      series = []
      if n < 0: 
          print("Incorrect input") 
      else: 
          series.append(a)
          if n > 0:
              series.append(b)
          for i in range(2, n+1): 
              c = a + b 
              a = b 
              b = c 
              series.append(b)
          print(series)