what exercise should I do to get rid of my underarm fats?

[Xiao Zhu]

I'm sorry I don't know what is it called? but you understand me right? the fats that slip out in our underarm when we are wearing sleeveless... if you know what is it called, kindly tell me please.. and what exercise should I do so that I'll be confident the next time I wear sleeveless.. thank you ü