#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: huxuanchen
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2076 kb
****************************************************************/