Find the errors in the following sentence and rewrite it using the correct grammar:
I have used the program for months and it's working great.
The sentence is already grammatically correct. No changes needed.
Complete the following task based on the instruction and optional input provided.### Instruction:
Find the errors in the following sentence and rewrite it using the correct grammar:

### Input:
I have used the program for months and it's working great.

### Output:
The sentence is already grammatically correct. No changes needed.