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

[Q]: Sentence: 'a man is standing on a snowboard, atop a mountain'. Replace the letter 'd' with 'u' in the sentence.
[A]: a man is stanuing on a snowboaru, atop a mountain


[Q]: Sentence: 'a boy taking a nap with his dog on a bed'. Replace the letter 'o' with 'i' in the sentence.
[A]: a biy taking a nap with his dig in a bed


[Q]: Sentence: 'two electric trains pass each other on the tracks'. Replace the letter 'c' with 'u' in the sentence.
[A]:
two eleutriu trains pass eauh other on the trauks