#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,a,b,c,d;
	cin>>n;
	a=n%10;
	b=n/10%10;
	c=n/100%10;
	d=n/1000;
	if(a==d&&b==c){
		cout<<"yes";
	}else{
		cout<<"no";
	}
}
/**************************************************************
	Problem: 1647
	User: sucongyi
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/