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

Input: Consider Input: Sentence: 'a red stop sign with street signs above it'. Find frequency of the letter 't'

Output: 5


Input: Consider Input: Sentence: 'a girl hitting a tennis ball on a court'. Find frequency of the letter 'l'

Output: 3


Input: Consider Input: Sentence: 'two people are hiking up a snowy mountain with skis attached to their backs'. Find frequency of the letter 'h'


Output: 4