#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0); cout.tie(0);
  ios::sync_with_stdio(false);
  int N;
  cin >> N;
  string S;
  cin >> S;
  S += 'n';
  bool ok = true;
  for(int i = 0; i < N; i++) {
    if(S[i] == 'n') {

    } else if(S[i] == 'w') {
      if(S[i + 1] == '?' || S[i + 1] == 'o' || S[i + 1] == 'a') {
        i++;
      } else {
        ok = false;
      }
    } else if(S[i] == '?') {
      if(S[i + 1] == 'o' || S[i + 1] == 'a') {
        i++;
      }
    } else {
      ok = false;
    }
  }
  cout << (ok ? "Yes" : "No") << '\n';
  return 0;
}