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 Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.*;

class Main
{
    public static void main (String[] args)
    {
        Scanner sc = new Scanner(System.in);

        String s = sc.next();
        int[] a = new int[s.length()];
        for(int i = 0; i < a.length; i++){
            if(s.charAt(i) == '0'){
                a[i] = 0;
            }
            else{
                a[i] = 1;
            }
        }
        int ans = 1;
        for(int i = 1; i < a.length - 1; i++){
            int count = 0;
            for(int j = 0; j < a.length - i + 1; j++){
                if(a[j] == 1){
                     count++;
                     for(int l = 1; l < i; l++){
                         a[j + l] = (a[i] == 0) ? 1 : 0;
                     }
                }
            }
            int key = 0;
            for(int k = 0; k < i; k++){
                key += a[a.length - 1 - k];
            }
            if(key == 0){
                ans = Math.max(ans, count);
            }
        }
        System.out.println(ans);
    }
}