#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";
}
}