#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,g,s,h;
	cin>>n;
	g=n/1000;
	s=n/10%10;
	h=n+s*10+s*100+g*1000;
	if(n==h){
		cout<<"yes";
	}else{
	    cout<<"no";
	}
}
/**************************************************************
	Problem: 1647
	User: wangyiyang
	Language: C++
	Result: Wrong Answer
****************************************************************/