#include<iostream>
using namespace std;

int main()
{
	string str;
	while( getline( cin, str ) )
	{
		string rev;
		for( int i = str.length()-1 ; i >= 0 ; i-- )
			rev += str[i];
		
		if( rev == str )
			cout << "yes\n";
		else
			cout << "no\n";
	}
	return 0;
}