input: Write a function to determine the Chinese zodiac sign for a specified year.
  assert chinese_zodiac(1997) == 'Ox'
  assert chinese_zodiac(1998) == 'Tiger'
  assert chinese_zodiac(1994) == 'Dog'
output: def chinese_zodiac(year):
      zodiacs = ['Rat', 'Ox', 'Tiger', 'Rabbit', 'Dragon', 'Snake', 'Horse', 'Goat', 'Monkey', 'Rooster', 'Dog', 'Pig']
      return zodiacs[(year - 1900) % 12]