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

[EX Q]: Sentence: 'the two dogs are playing in the pen together'. Find frequency of the letter 'o'
[EX A]: 3

[EX Q]: Sentence: 'two pepperoni pizzas and a cup on a counter'. Find frequency of the letter 'u'
[EX A]: 2

[EX Q]: Sentence: 'soft toy teddy bears and other toys in a trolley'. Find frequency of the letter 'e'
[EX A]:
4