text: #include <iostream>
  using namespace std;
  int dp[1010][1010];
  int main() {
  	string s;
  	getline(cin, s);
  	int len = s.length(), ans = 1;
  	for (int i = 0; i < len; i++) {
  		dp[i][i] = 1;
  		if (i < len - 1 && s[i] == s[i+1]) {
  			dp[i][i+1] = 1;
  			ans = 2;
  		}
  	}
  	for (int L = 3; L <= len; L++)
  		for (int i = 0; i + L - 1 < len; i++) {
  			int j = i + L - 1;
  			if (s[i] == s[j] && dp[i+1][j-1] == 1) {
  				dp[i][j] = 1;
  				ans = L;
  			}
  		}
  	printf("%d", ans);
  	return 0;
  }
  