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

Input: Consider Input: Sentence: 'a tennis player that is running to get the tennis ball'. Find frequency of the letter 't'

Output: 7


Input: Consider Input: Sentence: 'a woman is looking at sheep off in a field'. Find frequency of the letter 'm'

Output: 1


Input: Consider Input: Sentence: 'a man riding a bike on a sidewalk, pulling two horses behind him'. Find frequency of the letter 'd'


Output: 3