#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  string s;
  getline(cin, s);
  bool ans = true;
  rep(i, s.size()) {
    if (i % 2 == 0 && islower(s[i])) continue;
    if (i % 2 == 1 && s[i] == ' ') continue;
    ans = false;
  }
  cout << (ans ? "Yes" : "No") << endl;
  return 0;
}