#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001


int main(){
	
	string s;
	cin>>s;
	if(s[0]==s[1])cout<<"Yes"<<endl;
	else cout<<"No"<<endl;
	
	return 0;
}