#include <iostream> #include <algorithm> #include <iomanip> #include <map> #include <set> #include <queue> #include <stack> #include <numeric> #include <bitset> #include <cmath> static const int MOD = 1000000007; using ll = long long; using u32 = uint32_t; using namespace std; template<class T> constexpr T INF = ::numeric_limits<T>::max()/32*15+208; int main() { string s; getline(cin, s); int ok = 1; for (int i = 0; i < s.size(); ++i) { if(i&1){ if(s[i] != ' ') ok = 0; }else { if(!islower(s[i])) ok = 0; } } puts(ok ? "Yes" : "No"); return 0; }