## BTHSP - Back to High School Physics

A particle has initial velocity and constant acceleration. If its velocity after certain time is *v* then what will its displacement be in twice of that time?

### 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* (-100 <= *v* <= 100) and *t* (0<=*t*<= 200) (*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.

### Example

Input:`0 0`

5 12Output:

`0`

120

Added by: | Coach UTN FRSF |

Date: | 2011-03-11 |

Time limit: | 0.100s-1.600s |

Source limit: | 50000B |

Memory limit: | 1536MB |

Cluster: | Cube (Intel G860) |

Languages: | All |

Resource: | (UVa ACM) http://acm.uva.es/p/v100/10071.html |