Contest Duration: - (local time) (100 minutes) Back to Home
A - Takoyaki /

Time Limit: 2 sec / Memory Limit: 1024 MB

### 問題文

たこ焼き器を使うと、1 度に最大で X 個のたこ焼きを作ることができます。これにかかる時間は作る個数によらず T 分です。

N 個のたこ焼きを作るためには何分必要ですか？

### 制約

• 1 \leq N,X,T \leq 1000
• 入力は全て整数

### 入力

N X T


### 出力

N 個のたこ焼きを作るために必要な時間の最小値を整数で出力せよ。

### 入力例 1

20 12 6


### 出力例 1

12


6 分で 12 個作れるとは、1 分で 2 個作れるという意味ではないことに注意してください。

### 入力例 2

1000 1 1000


### 出力例 2

1000000


Score : 100 points

### Problem Statement

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.

### Sample Input 1

20 12 6


### Sample Output 1

12


He can make 12 pieces of takoyaki in the first 6 minutes and 8 more in the next 6 minutes, so he can make 20 in a total of 12 minutes.

Note that being able to make 12 in 6 minutes does not mean he can make 2 in 1 minute.

### Sample Input 2

1000 1 1000


### Sample Output 2

1000000


It seems to take a long time to make this kind of takoyaki.