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

Input: Consider Input: Sentence: 'the man is holding a plastic sled with snow in it next to a child'. Find frequency of the letter 'g'

Output: 1


Input: Consider Input: Sentence: 'a silver train crossing the road on tracks'. Find frequency of the letter 'r'

Output: 5


Input: Consider Input: Sentence: 'a man standing on one foot holding a skateboard behind him'. Find frequency of the letter 'a'


Output: 6