#include #include #include #include #include #include typedef long long ll; using namespace std; int main(){ string s; getline(cin, s); for (int i = 0; i < s.length(); ++i){ if ((i + 1) % 2 && !('a' <= s[i] && s[i] <= 'z')){ cout << "No" << endl; exit(0); } if (!((i + 1) % 2) && s[i] != ' '){ cout << "No" << endl; exit(0); } } cout << "Yes" << endl; return 0; }