func_code: def fibonacci(n):
      inc1 = 1
      inc2 = 0
      inc3 = ''
      l1 = [0]
      for fib in range(0, n + 1):
          inc3 = inc2
          inc2 = inc1
          inc1 = inc3 + inc2
          l1.append(inc3)
      return l1[n]