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

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 stop sign near a rail road crossing sign'. Find frequency of the letter 'g'

Output: 3


Input: Consider Input: Sentence: 'a road is shown with trash and animals next to it'. Find frequency of the letter 'n'


Output: 4