input: Write a python function to return the nth term in the Fibonacci sequence.
  assert nth_term_fibonacci(0) == 0
  assert nth_term_fibonacci(1) == 1
  assert nth_term_fibonacci(5) == 3
  assert nth_term_fibonacci(10) == 34
  assert nth_term_fibonacci(-1) == "Incorrect input"
output: def nth_term_fibonacci(n):
      if n < 0:
          return "Incorrect input"
      elif n == 0:
          return 0
      elif n == 1:
          return 1
      else:
          a, b = 0, 1
          for _ in range(2, n):
              a, b = b, a + b
          return b