#include <iostream>
#include <algorithm>
#include <string>
using namespace std;


int hantei(string s){
int n=s.length();
int a=1;
for(int i=0;i<n;i++){
//cout<<s[i]<<" "<<s[n-i-1]<<endl;
if(s[i]!=s[n-i-1]){
a=0;
//cout<<"b"<<endl;
break;
}

}

return a;

}



int main() {


int c=1;
string s;
cin>>s;
int i=s.length()-1;
while(i>0 && c==1){
for(int k=0;k<=s.length()-i;k++){
if(hantei(s.substr(k,i))==1){
cout<<i<<endl;
c=0;
break;
}

}
i--;


}



	return 0;
}