Ice Cream

Time limit2sMemory limit1024 MB

Summary

Find the minimum cost of a tower at least S cm tall, where the base costs 250 yen and gives A cm and each extra layer costs 100 yen and adds B cm.

Level: Easy1 of 10
Topics: Math, Implementation, Brute force
Solved: No attempts yet

Problem

The JOI ice cream shop is famous for its ice cream towers, which can be stacked very high. An ice cream tower consists of a base ice cream with 0 or more additional ice creams stacked on top of it.

The base ice cream costs 250 yen and is A cm tall. Each additional ice cream costs 100 yen, and adding one increases the height of the ice cream tower by B cm.

You want to buy an ice cream tower that is at least S cm tall at this shop. Find the minimum amount of money needed to buy an ice cream tower that is at least S cm tall.

Input

The input is given from standard input in the following format.

S
A
B

Output

Print the minimum amount of money needed to buy an ice cream tower that is at least S cm tall, omitting the unit (yen).

Constraints

1 ≦ S ≦ 100.
1 ≦ A ≦ 100.
1 ≦ B ≦ 100.
All input values are integers.

Examples3

Example 1
Input
```
28
20
5
```
Expected output
```
450
```
Example 2
Input
```
1
100
1
```
Expected output
```
250
```
Example 3
Input
```
100
1
1
```
Expected output
```
10150
```