#include <iostream>

using namespace std;

int main()

{

string input;

while (cin >> input) {

for (int i = 0; i < input.length(); i++) {

if (input[i] == input[input.length() - i - 1]) {

cout << "yes" << endl;

break;

}

else

{

cout << "no" << endl;

break;

}

}

}

return 0;

}