12+5+5+2=<<12+5+5+2=24>>24 minutes are accounted for.

There are 30-24=<<30-24=6>>6 minutes of ads.

# Answer

6
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
The half-hour newscast includes 12 minutes of national news, 5 minutes of international news, 5 minutes of sports, and 2 minutes of weather forecasts. The rest is advertisements. How many minutes of advertising are in the newscast?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
6
The half-hour newscast includes 12 minutes of national news, 5 minutes of international news, 5 minutes of sports, and 2 minutes of weather forecasts. The rest is advertisements. How many minutes of advertising are in the newscast?
train