#include <iostream>
#include <string>

using namespace std;

int main()
{
	string str;
	while(cin>>str)
	{
		//getline(cin,str);
		string::iterator it;
		string::reverse_iterator rit;
		bool isReversed=true;
		for ( it=str.begin() , rit=str.rbegin() ; rit < str.rend() && it<str.end(); it++ , rit++ )
		{
			while(!isalpha(*it))
			{
				it++;
			}
			while(!isalpha(*rit))
			{
				rit++;
			}

			if(tolower(*it)!=tolower(*rit))
			{
				isReversed=false;
				break;
			}

		}

		if(isReversed)
		{
			cout<<"yes"<<endl;
		}
		else
		{
			cout<<"no"<<endl;
		}
	}
    return 0;
}