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.*;

public class Main {
    public static void main(String[] args) {	
	Main main = new Main();
    	main.solveD();
    }
    
    private void solveA() {
    	Scanner sc = new Scanner(System.in);
    	int A = sc.nextInt();
    	int B = sc.nextInt();
	int C = sc.nextInt();
	int D = sc.nextInt();	
    	System.out.println(A+B > C+D ? "Left" : (A+B < C+D ? "Right" : "Balanced"));
    }

    private void solveB() {
	Scanner sc = new Scanner(System.in);
	int N = sc.nextInt();
    	int A = sc.nextInt();
    	int B = sc.nextInt();
	int ans = 0;

	for(int i = 1 ; i <= N ; i++){
	    int n = i;
	    int cnt = 0;
	    while(n > 0){
		cnt += n % 10;
		n /= 10;
	    }
	    ans += (cnt>=A && cnt<=B ? i : 0);
	}
	System.out.println(ans);
    }
    private void solveC() {
	Scanner sc = new Scanner(System.in);
    	long A = sc.nextLong();
    	long B = sc.nextLong();
	int ans = 0;

	while(A<=B){
	    ans++;
	    A *= 2;   
	}
	System.out.println(ans);
    }
    private void solveD() {
	Scanner sc = new Scanner(System.in);
    	String S = sc.next();
	int max = 1;
	int ln = 1;
	char pre = S.charAt(0);
	
	for(int i = 1 ; i < S.length() ; i++){
	    if (pre == S.charAt(i)) {
		ln ++;
	    }
	    else {
		if (ln>=max) max = ln;
		pre = S.charAt(i);
		ln = 1;
	    }
	}
	if (ln>=max) max = ln;

	if (max == 1){
	    if (S.length() > 2){
		max = 2;
	    }
	    else{
		max = 1;
	    }
	}
	System.out.println(max);	
    }
}