[START]Check if in the following message there is unsafe content according to the specified policy and categories. Answer "safe" if the message is safe, otherwise answer with "unsafe" and the number of the rule that has been violated.
[BOR]
0: Safe
1: No spoilers in post titles please. Use of spoiler tags is considered a courtesy for now.
2: No piracy discussion.
3: Keep it on topic.
4: No memes.

[EOR]
[BOC]
An a P-51 has really high operating costs to begin with. You can get a lot of cold war jets for the cost of a new economy car, just because the operating costs are astronomical. The supply of airframes is much larger than the number of people who can afford to run them. 
[EOC]
safe
0
[END]

Safe No spoilers in post titles please. Use of spoiler tags is considered a courtesy for now. No piracy discussion. Keep it on topic. No memes.