#include <iostream> #include <string> using namespace std; int main() { string s; cin >> s; bool isPalin = true; int len = s.size(); for (int i = 0; i < len / 2; i++) { if (s[i] != s[len - 1 - i]) { isPalin = false; break; } } if (isPalin) cout << "yes" << endl; else cout << "no" << endl; return 0; }