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

int main() {
  string s{'2'};
  int n;
  {
    string t; cin >> t;
    s += t;
    s += '3';
    n = s.size();
  }
  int l = (n + 1) / 2 - 1;
  int r = n - 1 - l;
  char c = s[l];
  for (; s[l] == s[r] && s[l] == c; l--, r++);
  cout << r-1 << endl;
}
### Prompt

Your task is to create 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;

int main() {
  string s{'2'};
  int n;
  {
    string t; cin >> t;
    s += t;
    s += '3';
    n = s.size();
  }
  int l = (n + 1) / 2 - 1;
  int r = n - 1 - l;
  char c = s[l];
  for (; s[l] == s[r] && s[l] == c; l--, r++);
  cout << r-1 << endl;
}
```