#include<bits/stdc++.h>
using namespace std;
int main()
{
	string a;
	cin>>a;
	int n=a.size();
	int k=n/2;
	char c=a[n-k-1];
	for(int i=k+1;i<=n;++i)
	{
		//cout<<c<<" "<<a[n-i]<<" "<<a[i-1]<<endl;
		if(a[n-i]!=a[i-1]||a[n-i]!=c)
              break;
		else ++k;
	}
	cout<<k<<endl;
	return 0; 
 } 
### Prompt

Please provide a CPP coded solution to the problem described below:

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 a;
	cin>>a;
	int n=a.size();
	int k=n/2;
	char c=a[n-k-1];
	for(int i=k+1;i<=n;++i)
	{
		//cout<<c<<" "<<a[n-i]<<" "<<a[i-1]<<endl;
		if(a[n-i]!=a[i-1]||a[n-i]!=c)
              break;
		else ++k;
	}
	cout<<k<<endl;
	return 0; 
 } 
```