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

Input: Consider Input: Sentence: 'three elephants walk up a dirt trail from the water'. Find frequency of the letter 'l'

Output: 3


Input: Consider Input: Sentence: 'two bigger elephants standing with a small elephant'. Find frequency of the letter 't'

Output: 5


Input: Consider Input: Sentence: 'a dog on a motorcycle in front of people who are watching'. Find frequency of the letter 'g'


Output: 2