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.

Input

Input is given from Standard Input in the following format:
N K

Output

Print the answer.

Constraints

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

Sample Input 1

1 2

Sample Output 1

203

The condominium has two rooms 101 and 102.
We have 101+102=203.

Sample Input 2

3 3

Sample Output 2

1818

见题面 Input 部分

见题面 Output 部分