#define  _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <algorithm>
#include <utility>
#include <functional>
#include <cstring>
#include <queue>
#include <stack>
#include <math.h>
#include <iterator>
#include <vector>
#include <string>
#include <set>
#include <math.h>
#include <iostream> 
#include<map>
#include <iomanip>
#include <stdlib.h>
#include <list>
#include <typeinfo>
#include <list>
#include <set>
using namespace std;
#define MAX_MOD 1000000007
#define REP(i,n) for(long long i = 0;i < n;++i)
#define LONG_INF 100000000000000
bool determine(string s) {
	for (int i = 0;i < s.length() / 2;++i) {
		if (s[i] != s[s.length() - i-1]) return false;
	}
	return true;
}
int main() {
	iostream::sync_with_stdio(false);
	string s;
	cin >> s;
	int compare = 1;
	for (int i = 0;i < s.length();++i) {
		string now;
		for (int j = i;j < s.length();++j) {
			now.push_back(s[j]);
			if (i != 0 || j != s.length() - 1) {
				if (determine(now)) {
					compare = max(compare,1+j - i);
				}
			}
		}
	}
	cout << compare << endl;
	return 0;
}