instruction:
In this task, you need to replace a letter in the sentence with another given letter.
question:
Sentence: 'many street signs in front of a building while it is snowing'. Replace the letter 'r' with 'x' in the sentence.
answer:
many stxeet signs in fxont of a building while it is snowing


question:
Sentence: 'a white plate topped with two sandwich halves and a pile of potatoes chips'. Replace the letter 'o' with 'x' in the sentence.
answer:
a white plate txpped with twx sandwich halves and a pile xf pxtatxes chips


question:
Sentence: 'a tour bus advertises buddy holly and ritchie valens'. Replace the letter 'a' with 'c' in the sentence.
answer:

c tour bus cdvertises buddy holly cnd ritchie vclens