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

Input: Consider Input: Sentence: 'a picture of a toilet and toilet paper in a bathroom'. Find frequency of the letter 'o'

Output: 5


Input: Consider Input: Sentence: 'a plane with stairs next to it sitting in a large lot'. Find frequency of the letter 'i'

Output: 6


Input: Consider Input: Sentence: 'a commuter train travels past an empty train station'. Find frequency of the letter 'l'


Output: 1