Konpeito

Interview

Time limit2sMemory limit1024 MB

Summary

Given three counts A, B, C, find the minimum total pieces that must be added so all three counts become equal.

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

Problem

Aoi and Rin, students at JOI High School, decided to eat the same number of konpeito as their teacher, Ms. Rie, with all 3 of them taking part.

Aoi has eaten A pieces, Rin has eaten B pieces, and Ms. Rie has eaten C pieces. What is the minimum total number of konpeito they must eat additionally so that all 3 have eaten the same number of konpeito?

Given the numbers A, B, C of konpeito the 3 have eaten, write a program that finds the minimum number of konpeito to eat additionally.

Input

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

A B C

Output

Print the minimum number of konpeito to eat additionally on 1 line to standard output.

Constraints

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

Examples2

Example 1
Input
```
4 6 9
```
Expected output
```
8
```
Example 2
Input
```
35 35 35
```
Expected output
```
0
```