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

Input: Consider Input: Sentence: 'people playing wii bowling in a modern library'. Find frequency of the letter 'o'

Output: 3


Input: Consider Input: Sentence: 'a airplane view of a big factory some people and cars'. Find frequency of the letter 'f'

Output: 2


Input: Consider Input: Sentence: 'a woman holds some baked goods at the convention'. Find frequency of the letter 'd'


Output: 3