#include <iostream>
#include <fstream>
#include <vector>
#include <map>
#include <algorithm>

using namespace std;

bool is_roop(vector<char> s, int left, int tail) {
	while (left < tail) {
		if (s[left] != s[tail])
			return false;
		left++;
		tail--;
	}
	return true;
}

int main(void) {
	std::ios::sync_with_stdio(false);
	std::cin.tie(0);
	std::cout << std::fixed;

	vector<char> s;
	int ans = 1;
	char c;

	while (cin >> c)
		s.push_back(c);

	int tail = s.size() - 1;

	for (int left = 0; left < tail; left++) {
		int right = tail;
		while (left < right) {
			if (s[left] == s[right]) {
				if (is_roop(s, left, right))
					ans = max(ans, right - left + 1);
			}
			right--;
		}
	}

	cout << ans << endl;
}