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

Input: Consider Input: Sentence: 'an orange cat sitting on the ground next to a  purse'. Find frequency of the letter 's'

Output: 2


Input: Consider Input: Sentence: 'the two dogs are playing in the pen together'. Find frequency of the letter 'o'

Output: 3


Input: Consider Input: Sentence: 'this dish has a slice cut from it'. Find frequency of the letter 's'


Output: 4