need to gain weight within a few months

[fanman.]

Well, I'm at it again. I'm going in another of those tournaments where I'm probably gonna be against people who are better than me. But my main concern is getting into the right devision. At the moment, I weigh 64kgs. If I am at this same weight at the time of the tournament (A few months), I will be in a devision where I might need to go against this guy who everybody's scared of. He will be in the under 65kg devision.
So, I want to reach 66kgs within a few months. In other words, I want to gain two or three kgs within a few months. But I don't want any negative effects on my health.
HOW DO I DO THIS?

[Tom Yum]

"Instead of chewing gum, chew bacon!"

"Wipe your food on a white napkin. If the napkin becomes transparent you are on your way to healthy weight gain!"

Seriously, try taking a weight gainer shake. That might add a few pounds on you within a month or so.

[shadowkiller]

just up your calories. Keep exercising the same as what you are now, or even scale it back a little. You will gain weight trust me. It shouldnt be hard to gain 2-3 kg in 3 months. Hell I can do it in 2 weeks.