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

Input: Consider Input: Sentence: 'a picture of two computers on a table'. Find frequency of the letter 'r'

Output: 2


Input: Consider Input: Sentence: 'a little boy that has a toothbrush in his mouth'. Find frequency of the letter 'r'

Output: 1


Input: Consider Input: Sentence: 'a lady on the beach flying a kite'. Find frequency of the letter 't'


Output: 2