Problem Statement

A condominium AtCoder has $N$ floors, called the $1$-st floor through the $N$-th floor. Each floor has $K$ rooms, called the $1$-st room through the $K$-th room.

Here, both $N$ and $K$ are one-digit integers, and the $j$-th room on the $i$-th floor has the room number i0j. For example, the $2$-nd room on the $1$-st floor has the room number $102$.

Takahashi, the manager, got interested in the sum of the room numbers of all rooms in the condominium, where each room number is seen as a three-digit integer. Find this sum.

Constraints

• $1 \leq N,K \leq 9$
• $N$ and $K$ are integers.

Input

Input is given from Standard Input in the following format:

N K

Output

Print the answer.