#include <bits/stdc++.h>
using namespace std;

bool isFunc(const string &s) {
  for (int i = 1; i < s.size(); i += 2)
    if (s[i] != ' ') return false;
  for (int i = 0; i < s.size(); i += 2)
    if (s[i] == ' ') return false;
  return true;
}

void solve() {
  string s;
  getline(cin, s);
  cout << (isFunc(s) ? "Yes" : "No") << endl;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  solve();
  getchar();
}