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

Input: Consider Input: Sentence: 'a girl hitting a tennis ball on a court'. Find frequency of the letter 'l'

Output: 3


Input: Consider Input: Sentence: 'a silver train crossing the road on tracks'. Find frequency of the letter 'r'

Output: 5


Input: Consider Input: Sentence: 'a woman holding a pole skying on the snow'. Find frequency of the letter 'g'


Output: 2