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

Input: Consider Input: Sentence: 'a large grass pasture land with sheep grazing on grass'. Find frequency of the letter 'a'

Output: 7


Input: Consider Input: Sentence: 'this is a close up view of a tennis player during the game'. Find frequency of the letter 't'

Output: 3


Input: Consider Input: Sentence: 'guy jumping a skate board down concrete stairs'. Find frequency of the letter 'e'


Output: 3