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

Input: Consider Input: Sentence: 'a bird outside standing on a table looking up'. Find frequency of the letter 'b'

Output: 2


Input: Consider Input: Sentence: 'group of cars on the road with the sun setting behind it'. Find frequency of the letter 'd'

Output: 2


Input: Consider Input: Sentence: 'two astros fans use their cell phones in the stands'. Find frequency of the letter 'u'


Output: 1