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 fire hydrant opened and spilling water'. Find frequency of the letter 'd'

Output: 4


Input: Consider Input: Sentence: 'a man in a sweatshirt is taking his own picture'. Find frequency of the letter 'u'

Output: 1


Input: Consider Input: Sentence: 'a beige bathroom with a long bathtub in it'. Find frequency of the letter 'o'


Output: 3