C2638 Exchange for Mig 29smt

A fighter, there are a lot of improved models, so just say the first model, don't follow up, start comparing performance, that's the absolute layman.

Different postfix represented different improvements. Take the MiG 29 fighter aircraft as an example. The initial model. It was MiG-29B and MiG-29S. Later on... MiG-29M appeared. Compared to the original model... It had changed a lot. For example