Gems and Glasses

Vikas and Twinkle are the organizers of Eureka, a paper presentation competition. After an exhausting session of work, the evening before the competition, Twinkle challenged Vikas to a game. There are N glasses, numbered from 1 to N. They are empty at the beginning. There will be M rounds of the game. In each round, he is given two numbers L and R, and he has to put gems in all the glasses numbere