#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;
    			}
    			
    		}
    		
    	}else cout<<p;
    	
    	
    }
    //cout<<hw(s);

	return 0;
}



/**************************************************************
	Problem: 1134
	User: hongjiaming
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2076 kb
****************************************************************/