#include using namespace std; using i64 = long long; #define rep(i,s,e) for(i64 (i) = (s);(i) < (e);(i)++) #define all(x) x.begin(),x.end() #define let auto const template struct dynarr: std::vector { using std::vector::vector; using size_type = typename std::vector::size_type; auto&& operator[](size_type i) { return this->at(i); } auto&& operator[](size_type i) const { return this->at(i); } }; int main() { string s; cin >> s; for(int i = 0;i < s.size();i++) { if(i % 2 == 1) { if(s[i] != ' ') { cout << "No" << endl; return 0; } } else { if(s[i] == ' ') { cout << "No" << endl; return 0; } } } cout << "Yes" << endl; }