#include <iostream> #include <string> using namespace std; string str; bool isHuiWen (int right, int left) { for (int i = left, j = right; i <= (left + right) / 2; i++, j--) { if (str[i] != str[j]) { return false; } } return true; } int main () { getline (cin, str); int len = str.size(); int right; int left; for (int i = len; i >= 1; i--) { for (int j = 0; j <= len - i; j++) { left = j; right = j + i - 1; if(isHuiWen(right, left)) { cout << i << endl; return 0; } } } return 0; }