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

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

Output: 5


Input: Consider Input: Sentence: 'there is a woman pointing at something with her dog'. Find frequency of the letter 'i'

Output: 5


Input: Consider Input: Sentence: 'a modern style bathroom awaits hotel guests with fresh linens and toiletries'. Find frequency of the letter 'o'


Output: 5