Some particle starts moving from rest with constant acceleration. After time t from the start of the motion, the particle's velocity became v. What distance will the particle travel in time 2t?
Each line is a separate test and contains two integers — the particle's velocity v (0≤v≤100) and the time t (0≤t≤200), at which the particle reached this velocity.
For each test, print the distance the particle will move in time 2t on a separate line.