#define _USE_MATH_DEFINES
#include<stdio.h>
#include<string>
#include<iostream>
#include<cctype>
#include<cstdio>
#include<vector>
#include<stack>
#include<queue>
#include <algorithm>
#include<math.h>
#include<set>
#include<map>
#include<iomanip>

//#include<bits/stdc++.h>



using namespace std;

long h(long w){
	if(w%2==0)return w/2;
	for(long i=3;i*i<=w;i+=2)if(w%i==0)return w/i;
	return 1;
}


int main() {
	
	string p;
	cin>>p;
	int t=0;
	for(int i=0;i<p.size()-1;i++){
		string x=p.substr(i,1);
		for(int j=i+1;j<p.size();j++){
			x+=p[j];
			string a=x.substr(0,x.size()/2);
			string b=x.substr(x.size()-x.size()/2,x.size()/2);
			reverse(b.begin(),b.end());
			if(a==b)t=max(t,j-i+1);
		}
	}
	cout<<t<<endl;

	return 0;
}