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

Input: Consider Input: Sentence: 'two men in black wet suits beside a white surfboard'. Find frequency of the letter 'e'

Output: 5


Input: Consider Input: Sentence: 'a person is holding a chocolate doughnut with rainbow sprinkles'. Find frequency of the letter 's'

Output: 4


Input: Consider Input: Sentence: 'a man with a straw in his mouth and an obscure look'. Find frequency of the letter 'w'


Output: 2