#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,g,s,b,q;
	cin>>n;
	g=n%10;
	s=n/10%10;
	b=n/100%10;
	q=n/1000%10;
	if(g==q)cout<<"yes"<<endl;
	else cout<<"no"<<endl;
	return 0;
}

/**************************************************************
	Problem: 1647
	User: admin
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/