A particle has initial constant velocity. For a particle with initial velocity v find the displacement of that
particle if the time t is doubled.
The input will contain two integers in each line. Each line makes one set of input. These two integers
denote the value of v (-10000 <= v <= 10000) and t(0<=t<= 500) ( t means at the time the particle gains
For each line of input print a single integer in one line denoting the displacement in double of that time.