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

Q: Sentence: 'a small bird perched on some thin branches'. Replace the letter 'a' with 'f' in the sentence.

A: f smfll bird perched on some thin brfnches
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Q: Sentence: 'people wait for a train on a snowy sidewalk'. Replace the letter 'n' with 'm' in the sentence.

A: people wait for a traim om a smowy sidewalk
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Q: Sentence: 'a traffic light hanging over a city street'. Replace the letter 'i' with 'c' in the sentence.

A:
a traffcc lcght hangcng over a ccty street
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