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

Input: Consider Input: Sentence: 'food sitting in bowls on table with checked tablecloth'. Find frequency of the letter 't'

Output: 6

Input: Consider Input: Sentence: 'a man riding a skateboard up the side of a ramp'. Find frequency of the letter 'u'

Output: 1

Input: Consider Input: Sentence: 'a young person is waiting patiently on the railing while on their skateboard'. Find frequency of the letter 'u'
Output: 1