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 skating down a stair rail in front of a bunch of people'. Find frequency of the letter 'o'

Output: 5


Input: Consider Input: Sentence: 'two bears swim in a blue pool of water'. Find frequency of the letter 'o'

Output: 4


Input: Consider Input: Sentence: 'a female bundled up skier getting ready to ski'. Find frequency of the letter 'p'


Output: 1