p02576 AtCoder Beginner Contest 176 - Takoyaki
Takahashi loves takoyaki - a ball-shaped snack.

With a takoyaki machine, he can make at most X pieces of takoyaki at a time, taking T minutes regardless of the number of pieces to make.

How long does it take to make N takoyaki?

Constraints

* 1 \leq N,X,T \leq 1000
* All values in input are integers.

Input

Input is given from Standard Input in the following format:


N X T


Output

Print an integer representing the minimum number of minutes needed to make N pieces of takoyaki.

Examples

Input

20 12 6


Output

12


Input

1000 1 1000


Output

1000000
```python
n,x,t=map(int,input().split())
print(abs((-n//x))*t)
```