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

Input: Consider Input: Sentence: 'two bears swim in a blue pool of water'. Find frequency of the letter 'o'

Output: 4


Input: Consider Input: Sentence: 'a group of people are playing soccer on a beach'. Find frequency of the letter 'l'

Output: 2


Input: Consider Input: Sentence: 'street light covered with different street signs, including street name and parking rules'. Find frequency of the letter 'l'


Output: 3