#include<bits/stdc++.h>
using namespace std;
bool  hw(string s){
    bool r=true;    
    for(int i=0;i<=(s.size()-1)/2;i++){
         if(s[i]!=s[s.size()-1-i]){
            r=false;
            break;
         }
     //cout<<s[i]<<" "<<s[s.size()-1-i]<<endl;
    }
    return r;
}
int main(){
      
    string s;
    cin>>s;
    int p=s.size();
    if(p%2==1) cout<<p;
    else{
        if(hw(s)){
        	 while(p!=0){
            	p=p/2;
                s=s.substr(0,p);
                if(hw(s)==false){
                	cout<<p;
                    break;
                } 
            }
                
        }
           
                    
	}
	return 0;
}

/**************************************************************
	Problem: 1134
	User: linmiaoling
	Language: C++
	Result: Accepted
	Time:6 ms
	Memory:2076 kb
****************************************************************/