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

Example Input: Sentence: 'an overhead view of a city cross walk on a rainy day features an array of colorful umbrellas'. Replace the letter 's' with 'd' in the sentence.
Example Output: an overhead view of a city crodd walk on a rainy day featured an array of colorful umbrellad

Example Input: Sentence: 'a mobile phone and a set of keys on a key chain'. Replace the letter 's' with 'j' in the sentence.
Example Output: a mobile phone and a jet of keyj on a key chain

Example Input: Sentence: 'two giraffes look out form a zoo towards the city skyline'. Replace the letter 't' with 'y' in the sentence.
Example Output:
ywo giraffes look ouy form a zoo yowards yhe ciyy skyline