#include using namespace std; constexpr int MOD = 998244353; constexpr int MD = 1000000007; constexpr int INF = INT_MAX; constexpr long long LINF = LLONG_MAX; #define REP(i, n) for (int i = 0; i < (int)(n); i++) using ll = long long;using vi = vector;using vll = vector; template using ps = pair; template using vec = vector; template using pqg = priority_queue, greater>; // ascendent template int sz(const T& x) { return x.size(); } // a = min(a,b) template inline bool chmin(T& a, const S& b) { return (a > b ? a = b, 1 : 0); } template inline bool chmax(T& a, const S& b) { return (a < b ? a = b, 1 : 0); } ll mpow(int base, int exponent, int mod){ if(exponent == 0) return 1; ll c = mpow(base, exponent/2, mod); c *= c; c %= mod; if(exponent % 2 == 1){ c *= base; c %= mod; } return c; } /* auto push = [&](int r, int c){ if(r < 0 || c < 0 || r >= h || c >= w) return; if(dist[r][c] != -1) return; }; */ //dfs/bfs埋め込み用 /* class edge{ public: int to, weight; edge(int a, int b){ to = a; weight = b; } }; */ //template of edge /*class edge2{ public: int from, to, weight; edge2(int w, int a, int b){ from = w; to = a; weight = b; } }; bool comp(edge2 a, edge2 b){ return a.weight < b.weight; } */ //template of edge2 struct before_main_function { before_main_function() { cin.tie(0); ios::sync_with_stdio(false); cout << setprecision(20) << fixed; #define endl "\n" } } before_main_function; int main(int /*argc*/, char** /*argv*/){ string s; cin >> s; if(s[0] == s[1]) cout << "Yes\n"; else cout << "No\n"; return 0; }