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