The Euler function

The Euler function phi is an important kind of function in number theory, (n) represents the amount of the numbers which are smaller than n and coprime to n, and this function has a lot of beautiful characteristics. Here comes a very easy question: suppose you are given a, b, try to calculate (a)+ (a+1)+....+ (b)

There are several test cases. Each line has two integers a, b (2<a<b<3000000).

Output the result of (a)+ (a+1)+....+ (b)