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

Input: Consider Input: Sentence: 'two young ladies that are dancing in the room together'. Find frequency of the letter 'a'

Output: 4


Input: Consider Input: Sentence: 'a downhill skier with snow plumes behind them'. Find frequency of the letter 'i'

Output: 4


Input: Consider Input: Sentence: 'two shirtless men are playing with frisbees outside'. Find frequency of the letter 's'


Output: 6