#include<bits/stdc++.h>
using namespace std;
bool hw(string s){
    bool r=true;
    for(int i=0;i<s.size()/2;i++){
        if(s[i]!=s[s.size()-i-1]){
            r=false;
            break;
        }
    }
    return r;
}
int main(){
string s;
cin>>s;
int e=s.size();
if(e%2==1) cout<<e;
else{
    if(hw(s)){
        while(e!=0){
            e=e/2;
            s=s.substr(0,e);
            if(hw(s)==false){
                cout<<e;
                break;
            }
        }
    }else cout<<e;
}
    return 0;
}
/**************************************************************
	Problem: 1134
	User: chenyaohuo
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2076 kb
****************************************************************/