In this task, you need to replace a letter in the sentence with another given letter.

Ex Input:
Sentence: 'a person on a snow board flying through the air'. Replace the letter 'f' with 'n' in the sentence.

Ex Output:
a person on a snow board nlying through the air


Ex Input:
Sentence: 'there is a purse on the floor with its contents spilled out'. Replace the letter 'd' with 'v' in the sentence.

Ex Output:
there is a purse on the floor with its contents spillev out


Ex Input:
Sentence: 'a white post bus is parked outside of a building at a bus stop'. Replace the letter 's' with 'l' in the sentence.

Ex Output:

a white polt bul il parked outlide of a building at a bul ltop