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

Input: Consider Input: Sentence: 'a man hitting a tennis ball with a tennis racquet'. Find frequency of the letter 't'

Output: 6


Input: Consider Input: Sentence: 'a crowd of people standing in front of a green train'. Find frequency of the letter 'g'

Output: 2


Input: Consider Input: Sentence: 'a woman kneeling down next to a fire hydrant with cans of paint'. Find frequency of the letter 'o'


Output: 4