#include<bits/stdc++.h>
using namespace std;
int main(){
	int a,s,d,f,g;
	cin>>a;
	s=a%10;
	d=a/10%10;
	f=a/100%10;
	g=a/1000;
	if(s==g&&d==f){
		cout<<"yes";
	}else{
		cout<<"no";
	} 
}

/**************************************************************
	Problem: 1647
	User: tonghuawei
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/