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

Ex Input:
Sentence: 'a mouse and keyboard sitting on a wooden desk'. Replace the letter 'a' with 'n' in the sentence.

Ex Output:
n mouse nnd keybonrd sitting on n wooden desk


Ex Input:
Sentence: 'a man that is throwing a frizbee in the woods'. Replace the letter 'g' with 'u' in the sentence.

Ex Output:
a man that is throwinu a frizbee in the woods


Ex Input:
Sentence: 'there are many skiers going up and down this mountain'. Replace the letter 'h' with 't' in the sentence.

Ex Output:

ttere are many skiers going up and down ttis mountain