#include<bits/stdc++.h>
using namespace std;
bool huiwen(char s[]){
    bool r=true;
    for(int i=0;i<strlen(s)/ 2;i++){
        if(s[i] !=s[strlen(s)-1-i]){
            r=false;
            break;
        }
    }
    return r;
}
int main(){
    char s[1000];
    cin>>s;
    while(huiwen(s)==1&&strlen(s)%2==0){
        s[strlen(s)/2]='\0';
    }
    cout<<strlen(s)<<endl;
    return 0;
}
/**************************************************************
	Problem: 1134
	User: luyanchen
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/