input: Write a python function to print the first n elements of a list.
  assert print_n_elements(3, [1, 2, 3, 4, 5])==None
  assert print_n_elements(2, ['a', 'b', 'c', 'd'])==None
  assert print_n_elements(4, [10, 20, 30, 40, 50, 60])==None
output: def print_n_elements(n, lst):
      for i in range(n):
          print(lst[i])