Score : $200$ points
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
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 is given from Standard Input in the following format:
Print the answer.
The condominium has two rooms $101$ and $102$. We have $101+102=203$.