9807: ABC265 —— A - Apple
[Creator : ]
Description
A fruit store sells apples.
You may perform the following operations as many times as you want in any order:
- Buy one apple for $X$ yen (the currency in Japan).
- Buy three apples for $Y$ yen.
How much yen do you need to pay to obtain exactly $N$ apples?
You may perform the following operations as many times as you want in any order:
- Buy one apple for $X$ yen (the currency in Japan).
- Buy three apples for $Y$ yen.
How much yen do you need to pay to obtain exactly $N$ apples?
Input
Input is given from Standard Input in the following format:
```
$X$ $Y$ $N$
```
```
$X$ $Y$ $N$
```
Output
Print the answer as an integer.
Constraints
- $1 \leq X \leq Y \leq 100$
- $1 \leq N \leq 100$
- All values in input are integers.
- $1 \leq N \leq 100$
- All values in input are integers.
Sample 1 Input
10 25 10
Sample 1 Output
85
Buy three apples for 25 yen three times and one apple for 10 yen, and you will obtain exactly 10 apples for a total of 85 yen.
You cannot obtain exactly 10 apples for a lower cost, so the answer is 85 yen.
You cannot obtain exactly 10 apples for a lower cost, so the answer is 85 yen.
Sample 2 Input
10 40 10
Sample 2 Output
100
It is optimal to buy an apple for 10 yen 10 times.
Sample 3 Input
100 100 2
Sample 3 Output
200
The only way to obtain exactly 2 apples is to buy an apple for 100 yen twice.
100 100 100
3400