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.Scanner;
public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		long ans=s.length();
		long count0=0;
		long count1=0;
		long count2=1;
		long b=0;
		long count3=0;
		long st=0;
		char a='2';
		for(int i = 0; i<s.length(); i++){
			if(i!=0){
				if(a==s.charAt(i)){
					count2++;
				}else{
					count3++;
					st+=count2;
					if(count3==2){
						ans=Math.min(ans,st);
						count3=1;
						st=count2;
					}
					count2=1;
					b++;
				}
			}
			if(s.charAt(i)=='1'){
				count1++;
			}else{
				count0++;
			}
			a=s.charAt(i);
		}
		if(b<2){
			System.out.println(Math.max(count1, count0));
		}else{
			System.out.println(Math.min(ans,st+count2));
		}
	}
}