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

Input: Consider Input: Sentence: 'a woman sitting in front of a giant slice of cheese pizza'. Find frequency of the letter 'e'

Output: 4


Input: Consider Input: Sentence: 'group of snowboarders on a snowy trail overlooking a mountain'. Find frequency of the letter 'r'

Output: 5


Input: Consider Input: Sentence: 'a pizza next to two calzone's in boxes on a table'. Find frequency of the letter 'x'


Output: 2