Hotel rooms#8254

Hotel rooms

1 second

128 megabytes

Very easy

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 $m (n, m \leq 1 0^{6})$ m~(n, m \le 10^6).

Output

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

Examples

Example 1

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m (n, m \leq 1 0^{6})