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

Input: Consider Input: Sentence: 'a group of people standing on grass with a train in the background'. Find frequency of the letter 'n'

Output: 6


Input: Consider Input: Sentence: 'a few giraffes standing in a field looking around'. Find frequency of the letter 'e'

Output: 3


Input: Consider Input: Sentence: 'a street sign in front of a ramshackle building on a corner lot'. Find frequency of the letter 'e'


Output: 4