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

Input: Consider Input: Sentence: 'there is a baseball game on and a few people are watching'. Find frequency of the letter 'i'

Output: 2


Input: Consider Input: Sentence: 'group of cars on the road with the sun setting behind it'. Find frequency of the letter 'd'

Output: 2


Input: Consider Input: Sentence: 'a man in a blue shirt and blue shoes is playing tennis'. Find frequency of the letter 't'


Output: 2