Problem Statement

A Kadomatsu sequence is defined as follows: when 3 integers are arranged as $A$, $B$, $C$ from left to right,
all the values are distinct and the second largest integer among $A$, $B$, $C$ is either $A$ or $C$.

From what I've heard, it seems that many people hate Kadomatsu sequences.
You are given 3 positive integers $A$, $B$, $C$ in this order from left to right, forming a Kadomatsu sequence.
Perform the 3 operations below any number of times so that the conditions of a Kadomatsu sequence are no longer satisfied, at the minimum cost.

・At cost 1, subtract 1 from the integer $A$.
・At cost 1, subtract 1 from the integer $B$.
・At cost 1, subtract 1 from the integer $C$.

Input

$A$ $B$ $C$

$A$, $B$, $C$ are positive integers. $1 \le A,B,C \le 1000000000=10^9$.
The input $A$, $B$, $C$ always satisfies the conditions of a Kadomatsu sequence.

Output

Output the answer on one line.

Sample

3 5 1

2