#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int main(){
	string s;
	cin >> s;
	ll res = s.length()/2, l = s.length()-res, r = res-1;
	char c = s[res];
	while (res<s.length()) {
		res++;
		l--;
		r++;
		if (!(s[l] == c && s[r] == c)) {
			res--;
			break;
		}
	}
	printf("%lld\n",res);
	return 0;
}

### Prompt

Please formulate a cpp solution to the following problem:

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.

Examples

Input

010


Output

2


Input

100000000


Output

8


Input

00001111


Output

4

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int main(){
	string s;
	cin >> s;
	ll res = s.length()/2, l = s.length()-res, r = res-1;
	char c = s[res];
	while (res<s.length()) {
		res++;
		l--;
		r++;
		if (!(s[l] == c && s[r] == c)) {
			res--;
			break;
		}
	}
	printf("%lld\n",res);
	return 0;
}

```