## Description:

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.

## Input:

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

that velocity)

## Output:

For each line of input print a single integer in one line denoting the displacement in double of that time.

## Sample Input:

0 0

5 12

## Sample Output:

0

120

## Note:

undefined

本题由旧版NOJ导入，来源：Internet