In this task, you need to count the number of times the given letter appears in the given sentence.
--------
Question: Sentence: 'a police officer who is riding on a horse'. Find frequency of the letter 'p'

Answer: 1


Question: Sentence: 'a group of cars and house on truck passing in a street'. Find frequency of the letter 'i'

Answer: 2


Question: Sentence: 'a kitchen scene with a microwave, window, and decorations'. Find frequency of the letter 'n'

Answer:
5