Change the tone of the following sentence from formal to informal.
I regret to inform you that I will not be able to attend the meeting.
Bummer, I'm not gonna be able to make it to the meeting.
Complete the following task based on the instruction and optional input provided.### Instruction:
Change the tone of the following sentence from formal to informal.

### Input:
I regret to inform you that I will not be able to attend the meeting.

### Output:
Bummer, I'm not gonna be able to make it to the meeting.