Problem:
Score : 500 points

Problem Statement

You are given a string S consisting of 0 and 1.
Find the maximum integer K not greater than |S| such that we can turn all the characters of S into 0 by repeating the following operation some number of times.

Choose a contiguous segment [l,r] in S whose length is at least K (that is, r-l+1\geq K must be satisfied). For each integer i such that l\leq i\leq r, do the following: if S_i is 0, replace it with 1; if S_i is 1, replace it with 0.

Constraints

1\leq |S|\leq 10^5

S_i(1\leq i\leq N) is either 0 or 1.

Input

Input is given from Standard Input in the following format:

S

Output

Print the maximum integer K such that we can turn all the characters of S into 0 by repeating the operation some number of times.

Sample Input 1

010

Sample Output 1

2

We can turn all the characters of S into 0 by the following operations:

Perform the operation on the segment S[1,3] with length 3. S is now 101.

Perform the operation on the segment S[1,2] with length 2. S is now 011.

Perform the operation on the segment S[2,3] with length 2. S is now 000.

Sample Input 2

100000000

Sample Output 2

8

Sample Input 3

00001111

Sample Output 3

4

Solution in C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;


class MainClass
{
    public static void Main(string[] args)
    {

        string s = Console.ReadLine();
        char[] c = s.ToCharArray(); 


        for (int ans = c.Length; ans >= 1;ans--)
        {
            bool frg = true;

            for (int i = 0; i < c.Length;)
            {

                if(c[i] == '0')
                {
                    i = i + 1;
                    continue;
                }
                else
                {

                    if(i+ans -1 >= c.Length)
                    {
                        frg = false;
                        break;
                    }



                    for (int j = i; j < i + ans;j++)
                    {

                        if(c[j]=='1')
                        {
                            c[j] = '0';
                        }
                        else
                        {
                            c[j] = '1';
                        }   
                    }
                    pri(c);
                    i = i + 1;
                    continue;
                }

            }

            if (frg)
            {
                Console.WriteLine(ans);
                break;
            }

        }

    }

    public static void pri(char[] c)
    {
        for (int i = 0; i < c.Length;i++){
            Console.Write(c[i]);
        }
        Console.WriteLine("");
    }


}