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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>
#include<math.h>
#include<stdlib.h>


int main(){
	int i,j,k;
	short int S[1000001];
	char c;
	int right;
	int left;
	int N2;
	
	int N = 0;
	
	
	while( (c = getchar()) != EOF ){
		if(c == '1')S[N] = 1;
		if(c == '0')S[N] = -1;
		//putchar(c);fflush(stdout);
		N++;
	}//printf("\n");
	
	//右側で何桁連続で同じ数値が出てきているか
	right = 1;
	for(i=N-1;i>0;i--){
		if(S[i] == S[i-1])right++;
		else break;
	}
	
	//右側で何桁連続で同じ数値が出てきているか
	left = 1;
	for(i=0;i<N-1;i++){
		if(S[i] == S[i+1])left++;
		else break;
	}
	
	if(left>right)printf("%d\n",left);
	else printf("%d\n",right);
	
	
	
	return 0;
}