input: Write a function to find the age of a person given their name in a dictionary.
  assert find_age({'John': 20, 'Maria': 25}, 'John') == 20
  assert find_age({'John': 20, 'Maria': 25}, 'Maria') == 25
  assert find_age({'John': 20, 'Maria': 25, 'Alice': 30}, 'Alice') == 30
output: def find_age(ages, name):
      return ages.get(name)