#include <bits/stdc++.h>
#ifdef _DEBUG
#include "debug.hpp"
#else
#define debug(...)
#endif
#define fastIO (cin.tie(0), cout.tie(0), ios::sync_with_stdio(false))
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define precise(i) fixed << setprecision(i)
using ill = int64_t;
using ull = uint64_t;
using namespace std;
using std::cout;

bool isLower(char ch) {
  return 'a' <= ch && ch <= 'z';
}

void solve() {
  string s;
  getline(cin, s);

  for (size_t i = 0; i < s.size(); i++) {
    if ((i + 1) % 2 != 0) {
      if (!isLower(s.at(i))) {
        cout << "No" << '\n';
        return;
      }
    } else {
      if (s.at(i) != ' ') {
        cout << "No" << '\n';
        return;
      }
    }
  }
  cout << "Yes" << '\n';
}

void wrapper() {
  rep(i, 2) {
    cout << "[TEST " << i << "]\n";
    solve();
    cout << "\n";
  }
}

int main() {
  fastIO;
#ifdef _DEBUG
  wrapper();
#else
  solve();
#endif
}