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

Input: Consider Input: Sentence: 'one woman is arranging the other woman's hair'. Find frequency of the letter 'o'

Output: 4


Input: Consider Input: Sentence: 'a big bear walks through some grass'. Find frequency of the letter 'a'

Output: 4


Input: Consider Input: Sentence: 'a large group of people marching down a street'. Find frequency of the letter 'i'


Output: 1