#include #include using namespace std;

int main() { string s; getline(cin, s);

int left = 0, right = s.length() - 1;
bool isPalindrome = true;

while (left < right) {
    if (s[left] != s[right]) {
        isPalindrome = false;
        break;
    }
    left++;
    right--;
}

if (isPalindrome) {
    cout << "yes" << endl;
} else {
    cout << "no" << endl;
}

return 0;

}