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

Input: Consider Input: Sentence: 'two zebras standing around while a third zebra drinks from a pond'. Find frequency of the letter 's'

Output: 3


Input: Consider Input: Sentence: 'a red building with a crowd of people outside it near the water'. Find frequency of the letter 'e'

Output: 7


Input: Consider Input: Sentence: 'a male tennis player in a blue shirt is playing tennis'. Find frequency of the letter 'n'


Output: 6