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;

public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
        String s = sc.nextLine();
		sc.close();
		
        int ans1;
        if(s.length() %2 == 0){
            ans1 = s.length() / 2;
        }else{
            ans1 = s.length() / 2 + 1;
        }

        int ans2 = 0;
        int len = 1;
        int div = 1;
        ArrayList<Integer> lendata = new ArrayList<Integer>();
        for(int i=1; i<s.length(); i++){
            if(s.charAt(i) == s.charAt(i-1)){
                len++;
            }else{
                lendata.add(len);
                len = 1;
                div++;
            }
            if(len > ans2){
                ans2 = len;
            }
        }
        lendata.add(len);
        int ans3 = 0;
        if(div == 3){
            ans3 = Math.min(lendata.get(0), lendata.get(2)) + lendata.get(1);
        }

        System.out.println(Math.max(ans1, Math.max(ans2, ans3)));
	}
}