using namespace std;
int main()
{
	string s;
	getline ( cin, s );
	int len =s.size();
	int i = 0,j = len -1;
	while(j>i)
	{
		if ( s[j]!=s[i] )
		{
			cout<<"no"<<endl;
			return 0;
		 } 
		 i++;
		 j--;
	}
	
	
	
	
	cout<<"yes"<<endl;
	
	
	return 0;
 }