Problems

# Hotel rooms

# Hotel rooms

A hotel has **n** floors. The lobby, restaurant and gym are located on the first floor. The guestrooms are on **2**-nd to **n**-th floors. There are **m** standard rooms on each floor. If each standard room can fit **3** guests, what is the maximum number of guests that all the standard rooms can accommodate?

#### Input

Two positive integers **n** and **m** (**n**, **m** ≤ `10`

).^{6}

#### Output

Print the maximum number of guests that all the hotel standard rooms can accommodate.

Input example #1

5 10

Output example #1

120