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

Input: Consider Input: Sentence: 'a young man riding a skateboard near a forest'. Find frequency of the letter 'd'

Output: 2


Input: Consider Input: Sentence: 'a sailboat is floating near the rocky shore of a beach'. Find frequency of the letter 'o'

Output: 5


Input: Consider Input: Sentence: 'an old church with a clock on it is seen here'. Find frequency of the letter 'e'


Output: 4