#include<bits/stdc++.h>
using namespace std;
int f(int n,string s){
	for(int i=0;i<n/2;i++){
		if(s[n-i-1]!=s[i]){
			return 0;
		}
		
	}
	 return 1;
}
int main(){
	int n;
	string s,j;
	cin>>s;
	n=s.size();
	while(f(n,s)==1){
		n/=2;
		s=s.substr(0,n);
	}
	cout<<n;
	return 0;
}
/**************************************************************
	Problem: 1134
	User: houshanglin
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2076 kb
****************************************************************/