#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;
		}
	}
	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;	
	}
	return 0;
}
/**************************************************************
	Problem: 1134
	User: linzihang
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2076 kb
****************************************************************/