小磚頭(Small Brick) is a boy who love to do addition.
However, he never understand why 1+1 equals to 2 but not 11,
why is 3+33+333 equals to 369 but not 333333.
Until one day he saw a man programming in Python.
The man type: '3'+'33'+'333', magically, the answer is '333333'!
This breaking news astonished 小磚頭(Small Brick).
He run excitedly back to home, and told you the news.
However, you know that the answer is exactly not 333333.
Can you help 小磚頭(Small Brick) to find the correct answer?
Given a digit number A, and a number K.
We defined that S1=A, S2=AA, S3=AAA... .
Please calculate S1 + S2 + .. + SK.
For Example: A=3, K=3
then the answer is 3 + 33 + 333=369.
ouo.
Hint1: you can use long long type to store output
Hint2: you can use %lld to print long long type
Input contain only one line.
2 number A, K with a space between.
It is guarantee A is a digit number and 1 <= K <= 16.
Output the answer with a new line character at the end.