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

Input: Consider Input: Sentence: 'a blue fire hydrant painted on the bottom of it'. Find frequency of the letter 'h'

Output: 2


Input: Consider Input: Sentence: 'pedestrians pass by a stop sign, some holding surfboards'. Find frequency of the letter 'n'

Output: 3


Input: Consider Input: Sentence: 'a foggy day that has some lights by a road'. Find frequency of the letter 'y'


Output: 3