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

Input: Consider Input: Sentence: 'a bird in a tree looking up at branches'. Find frequency of the letter 'e'

Output: 3


Input: Consider Input: Sentence: 'a man sitting in front of a laptop computer next to a child'. Find frequency of the letter 'e'

Output: 2


Input: Consider Input: Sentence: 'a man flies a kite on a nearly cloudless day'. Find frequency of the letter 'l'


Output: 4