#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,a,b,c,d,x;
	cin>>n;
	a=n%10;
	b=n/10%10;
	c=n/100%10;
	d=n/1000;
	x=a*1000+b*100+c*10+d;
	if(x==n){
		cout<<"yes"; 
	}else{
		cout<<"no";
	}
	
}

/**************************************************************
	Problem: 1647
	User: zhengzihao3
	Language: C++
	Result: Accepted
	Time:14 ms
	Memory:2072 kb
****************************************************************/