#include <bits/stdc++.h>
#include<iostream>
#include<map>
#include<vector>
#include <algorithm>
#include<math.h>
#include <iomanip>
#include<set>
#include <numeric>
#include<string>
using ll = long long;
using namespace std;

int main()
{
    int n, i = 0;
    string s;
    cin >> n >> s;
    while (i < n){
        if(s[i] == '?'){
            if ((i+1 < n) && (s[i+1] == 'o' || s[i+1] == 'a')) i += 2;
            else i++;
        } else if(s[i] == 'w'){
            if ((i + 1 < n) && (s[i] == 'a' || s[i] == 'o' || s[i] == '?')) i++;
            else {
                cout << "No" << endl;
                return 0;
            }
        } else if (s[i] == 'n' || s[i] == '?') i++;
        else {
            cout << "No" << endl;
            return 0;
        }
    }
    cout << "Yes" << endl;
}