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.ArrayList;
import java.util.Scanner;

class Main{
	public static void main(String[]$){
		Scanner s=new Scanner(System.in);
		char[] c=s.next().toCharArray();
		ArrayList<Integer> l=new ArrayList<>();
		l.add(0);
		for(int i=1;i<c.length;++i)
			if(c[i]!=c[i-1])
				l.add(i);
		l.add(c.length);
		int max=0;
		if(l.size()==2)
			max=l.size();
		else if(l.size()==3)
			max=Math.max(l.get(1),c.length-l.get(1));
		else{
			for(int i=2;i<l.size();++i)
				max=Math.max(max,l.get(i)-l.get(i-2));
		}
		System.out.println(max);
	}
}