#include using namespace std; using ll = long long; using ld = long double; using vi = vector; using vvi = vector>; using vvvi = vector>>; using vl = vector; using vvl = vector>; using vvvl = vector>>; #define FOR(i, m, n) for (int i = (m); i < (n); i++) #define FORR(i, m, n) for (int i = (m); i >= (n); i--) #define REP(i, n) FOR(i, 0, (n)) #define REPR(i, n) FORR(i, (n) - 1, 0) #define REP1(i, n) FOR(i, 1, (n) + 1) #define REPS(c, s) for (char c : s) #define ALL(c) (c).begin(), (c).end() #define SORT(c) sort(ALL(c)) #define REV(c) reverse(ALL(c)) #define sz(v) (int)v.size() #define endl '\n' template inline bool chmin(T& a, T b) {if (a > b) {a = b; return true;} return false;} template inline bool chmax(T& a, T b) {if (a < b) {a = b; return true;} return false;} template inline void prn(vector& v) {int n = sz(v); REP(i, n) cout << v[i] << ' ';} template inline void printv(vector& v) {int n = sz(v); REP(i, n) cout << v[i] << (i == n - 1 ? endl : ' ');} template inline void printvv(vector>& v) {for (auto u : v) printv(u);} template inline void printlnv(vector& v) {int n = sz(v); REP(i, n) cout << v[i] << endl;} const int MOD = 1000000007; const int INF = 1000000001; const ll LINF = 1000000001000000001LL; void solve(); int main() { ios::sync_with_stdio(false); cin.tie(nullptr); cout << fixed << setprecision(numeric_limits::max_digits10); solve(); return 0; } void solve() { string s; getline(cin, s); int n = sz(s); bool ok = true; REP(i, n) if (i % 2 == 0) { if (s[i] == ' ') { ok = false; break; } } else { if (s[i] != ' ') { ok = false; break; } } cout << (ok ? "Yes" : "No") << endl; }