### COCI 2007/2008, Contest #3

## Task CETIRI

Mirko has chosen four integers which form an arithmetic progression. In other words, when the four
numbers are sorted, then the difference between each pair of **adjacent** elements is **constant**.

As has become usual, Mirko **lost** one of the numbers and also is not sure whether the remaining three
are in the correct (sorted) order.

Write a program that, given the three remaining numbers, finds the fourth number.

### Input

The input contains 3 integers between -100 and 100 on a single line, separated by single spaces.

**Note:** the input data will guarantee that a solution, although not necessarily unique, will always exist.

### Output

Output any number which could have been the fourth number in the sequence.

### Examples

## Input4 6 8 ## Output10 |
## Input10 1 4 ## Output7 |

All Submissions

Best Solutions

**Point Value:** 3

**Time Limit:** 1.00s

**Memory Limit:** 32M

**Added:** Jul 30, 2013

**Languages Allowed:**

C++03, PAS, C, HASK, ASM, RUBY, PYTH2, JAVA, PHP, SCM, CAML, PERL, C#, C++11, PYTH3

## Comments (Search)

It's quiet in here...