#include<iostream>
#include<set>
#include<algorithm>
#include<vector>
#include<string>
#include<set>
#include<map>
#include<numeric>
#include<queue>
#include<cmath>
using namespace std;
typedef long long ll;
const ll INF=1LL<<60;
typedef pair<int,int> P;
typedef pair<int,P> PP;
const ll MOD=998244353;

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