In this task, you need to count the number of times the given letter appears in the given sentence.

Ex Input:
Sentence: 'a white paper plate with a slice of pizza on it'. Find frequency of the letter 'h'

Ex Output:
2


Ex Input:
Sentence: 'a young girl is brushing her teeth in this dated photo'. Find frequency of the letter 't'

Ex Output:
5


Ex Input:
Sentence: 'a woman with a blue dress is playing tennis'. Find frequency of the letter 'h'

Ex Output:

1