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 paddle boarding by a boat dock in a city'. Find frequency of the letter 'o'

Output: 3


Input: Consider Input: Sentence: 'a person on a skateboard going down a ramp'. Find frequency of the letter 'n'

Output: 4


Input: Consider Input: Sentence: 'a pizza that is sitting on a table'. Find frequency of the letter 'e'


Output: 1