```cpp
#include<bits/stdc++.h>
using namespace std;
int n;
string a;
int main()
{
cin>>a;
n=a.size();
for(int i=1;i>0;i++)
{
for(int k=0,j=n-1;k<i;k++,j--)
{
if(a[k]!=a[j])
{
i=0;
break;
}
}
if(i==0 || n%2==1) break;
else n/=2;
}
cout<<n;
return 0;
}
```
by Shui_Dream @ 2018-07-26 18:37:11