CF1064A.Make a triangle!

Masha has three sticks of length $a$, $b$ and $c$ centimeters respectively. In one minute Masha can pick one arbitrary stick and increase its length by one centimeter. She is not allowed to break sticks.

What is the minimum number of minutes she needs to spend increasing the stick's length in order to be able to assemble a triangle of positive area. Sticks should be used as triangle's sides (one stick for one side) and their endpoints should be located at triangle's vertices.

玛莎有三根长度分别为 $a$、$b$ 和 $c$ 厘米的木棍。每分钟，玛莎可以任选一根木棍，将其长度增加 1 厘米。她不允许折断木棍。

为了能用这三根木棍组成一个面积为正的三角形（每根木棍作为三角形的一条边，且木棍端点需恰好位于三角形的三个顶点上），玛莎最少需要花费多少分钟来增加木棍长度？

The only line contains tree integers $a$, $b$ and $c$ ($1 \leq a, b, c \leq 100$) — the lengths of sticks Masha possesses.

唯一的一行包含三个整数 $a$、$b$ 和 $c$（$1 \leq a, b, c \leq 100$）——即玛莎所拥有的木棍长度。

Print a single integer — the minimum number of minutes that Masha needs to spend in order to be able to make the triangle of positive area from her sticks.

输出一个整数——玛莎需要花费的最少分钟数，以便能够用她的木棍拼出一个面积为正的三角形。

In the first example, Masha can make a triangle from the sticks without increasing the length of any of them.

In the second example, Masha can't make a triangle of positive area from the sticks she has at the beginning, but she can spend one minute to increase the length $2$ centimeter stick by one and after that form a triangle with sides $3$, $3$ and $5$ centimeters.

In the third example, Masha can take $33$ minutes to increase one of the $10$ centimeters sticks by $33$ centimeters, and after that take $48$ minutes to increase another $10$ centimeters stick by $48$ centimeters. This way she can form a triangle with lengths $43$, $58$ and $100$ centimeters in $81$ minutes. One can show that it is impossible to get a valid triangle faster.

在第一个例子中，玛莎无需增加任何木棍的长度即可用它们组成一个三角形。

在第二个例子中，玛莎最初拥有的木棍无法构成面积为正的三角形，但她可以花费一分钟将长度为 $2$ 厘米的木棍增加 $1$ 厘米，之后便能用边长分别为 $3$、$3$ 和 $5$ 厘米的木棍构成一个三角形。

在第三个例子中，玛莎可以花费 $33$ 分钟将一根 $10$ 厘米长的木棍延长 $33$ 厘米，再花费 $48$ 分钟将另一根 $10$ 厘米长的木棍延长 $48$ 厘米。这样，她便能在 $81$ 分钟内组成一个边长分别为 $43$、$58$ 和 $100$ 厘米的三角形。可以证明，无法以更短的时间得到一个合法的三角形。