#include <bits/stdc++.h> 
using namespace std;
int main()
{
    char s;
    cin>>s;
    for(int i=1,j=strlen(s);i<=strlen(s)/2;i++,j--)
	{
        if(s[i]!=s[j])
	   {
            cout<<"no"<<endl;
			return 0; 
        }
    }
    cout<<"yes"<<endl;
    return 0;
}