#include <string>

#include <iostream>

using namespace std;

int main()

{

bool ok = true;

string n;

cin >> n;

for (int i = 0; i < n.length() / 2; i++)

{

if (n[i] != n[n.length() - i - 1])

{

ok = false;

}

}

if (ok == true)

{

cout << "yes";

}

else

{

cout << "no";

}

}