#include<bits/stdc++.h>
using namespace std;
int main()
{
	string a;
	cin>>a;
	int n=a.size(),f=1,w=n/2+n%2;
	for(int i=0;i<n;i++) if(a[i]=='0')
	{
		f--;
		break;
	}
	if(f) printf("%d\n",n);
	else
	{
		for(;w<n;w++)
			if(a[w]!=a[w-1]||a[w]!=a[n-w-1])
				break;
		printf("%d",w);
	}
	return 0;
}
### Prompt

Your challenge is to write 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 a;
	cin>>a;
	int n=a.size(),f=1,w=n/2+n%2;
	for(int i=0;i<n;i++) if(a[i]=='0')
	{
		f--;
		break;
	}
	if(f) printf("%d\n",n);
	else
	{
		for(;w<n;w++)
			if(a[w]!=a[w-1]||a[w]!=a[n-w-1])
				break;
		printf("%d",w);
	}
	return 0;
}
```