#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <cmath>
#include <string>
#include <algorithm>
#include <vector>

using namespace std;


int main() {
#ifdef _DEBUG
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif
	ios::sync_with_stdio(false);
	string s;
	cin >> s;
	int size = s.size();
	int maxstr = 0;
	int max = 0;
	for (int i = 0; i < s.size()-max ; ++i) {

		for (int j = size-i;j>0; --j) {
			string s1 = s.substr(i, j);
			if (s1.size() % 2 == 0) {
				//cout << s1 << " ";
				string s2 = s1.substr(0, j / 2);
				string s3 = s1.substr(j / 2, j / 2);
				reverse(s3.begin(), s3.end());

				if (s2 == s3) {
					maxstr = s1.size();
					if (max < maxstr) {
						max = maxstr;
						break;
					}
				}
			}
			else {
				string s2 = s1.substr(0, j / 2);
				string s3 = s1.substr(j / 2+1, j / 2);
				reverse(s3.begin(), s3.end());

				if (s2 == s3) {
					maxstr = s1.size();
					if (max < maxstr) {
						max = maxstr;
						break;
					}
				}
			}
		}
		}
	cout << max;
	}