// 嘘解法 (TLE)
// DFS で全探索

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

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(15);

    int N;
    cin >> N;
    string S;
    cin >> S;

    string T = "waon?";
    for (auto s : S) {
        if (T.find(s) == string::npos) {
            cout << "No" << '\n';
            return 0;
        }
    }

    auto match = [&](string s, string p) -> bool {
        assert(s.size() == p.size());
        for (int i = 0; i < (int)s.size(); i++) {
            if (s[i] == p[i] || s[i] == '?') { continue; }
            return false;
        }
        return true;
    };

    vector<string> patterns = {"wa", "wo", "n"};

    // S[0,i) が wawon 文字列になっている
    auto dfs = [&](auto&& self, int i) -> void {
        if (i == N) {
            cout << "Yes" << '\n';
            exit(0);
        }
        for (auto p : patterns) {
            int n = p.size();
            if (i + n <= N && match(S.substr(i, n), p)) {
                self(self, i + n);
            }
        }
    };
    dfs(dfs, 0);

    cout << "No" << '\n';

    return 0;
}