#include<bits/stdc++.h>
#include <atcoder/all>
using namespace std;using namespace atcoder;using vst = vector<string>;using ll = long long;
using ld = long double;using pll = pair<ll,ll>;using vll = vector<ll>;using vvll = vector<vll>;
#define rep(i, n) for (ll i = 0; i < n; i++)
#define repp(i,k,n) for (ll i = k; i < n; i++)
#define per(i,s,e) for(ll i = s; i >= e; i--)
#define all(v) v.begin(),v.end()
#define no() {cout << "No" << endl; return 0;}
#define yes() {cout << "Yes" << endl;return 0;}
#define CHECK(a) a ? cout << "Yes" << endl : cout << "No" << endl
#define UNOmap unordered_map
#define UNOset unordered_set
#define ASC(T) T,vector<T>,greater<T>
template<class... T>void in(T&... a){(cin >> ... >> a);}
template<class T, class... Ts>void out(const T& a, const Ts&... b){cout << a;((cout << ' ' <<  b), ...);cout << '\n';}
void vin(vll &v){for(ll i = 0; i < (ll)v.size(); i++)in(v[i]);}
void vout(vll &v){for(ll i = 0; i < (ll)v.size(); i++) cout << v[i] << ' ';}
ll INF = 1LL << 62;ll MODD = 998244353;ll MOD = 1000000007;
// using mint = modint998244353;
// using mint = modint1000000007;
//using mint = modint;

//----------------------------------------------

map<string,bool> memo;

bool dfs(string s){
  if(memo.count(s)) return memo[s];
  if(s == "") return true;
  bool res = false;
  if(s.substr(0,2) == "wa" or s.substr(0,2) == "?a" or s.substr(0,2) == "w?"){
    string t = s;
    t.erase(0,2);
    res = res or dfs(t);
  }
  if(s.substr(0,2) == "wo" or s.substr(0,2) == "?o" or s.substr(0,2) == "w?"){
    string t = s;
    t.erase(0,2);
    res = res or dfs(t);
  }
  if(s[0] == 'n' or s[0] == '?'){
    string t = s;
    t.erase(0,1);
    res = res or dfs(t);
  }
  memo[s] = res;
  return res;
}


int main(){
  ll N; string s;
  in(N,s);
  CHECK(dfs(s));
 }