#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()-1-i]){
			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: linyuhang
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2076 kb
****************************************************************/