instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a lady mixes some things in a blender as people look on'. Find frequency of the letter 'i'
answer:
3


question:
Sentence: 'a crowd of people skiing and enjoying the snow'. Find frequency of the letter 'o'
answer:
5


question:
Sentence: 'a group of people on a field playing baseball'. Find frequency of the letter 'u'
answer:

1