#include <bits/stdc++.h>
using namespace std;
int main () {
	int N;
	cin >> N;
	bool ok[4] = {true, false, false, false};
	bool G[4][4] = {
		{false, true, true, false},
		{false, false, true, true},
		{false, true, true, false},
		{false, true, true, false}};
	string key = "?wnao";
	for (int i = 0; i < N; i ++) {
		char c;
		cin >> c;
		bool did = false;
		for (int j = 0; j < 5; j ++) {
			if (key[j] != c) {
				continue;
			}
			if (j) {
				j = min(j, 3);
				bool ok2[4];
				for (int k = 0; k < 4; k ++) {
					ok2[k] = false;
				}
				for (int k = 0; k < 4; k ++) {
					ok2[j] = ok2[j] || (ok[k] && G[k][j]);
				}
				for (int k = 0; k < 4; k ++) {
					ok[k] = ok2[k];
				}
			} else {
				bool ok2[4];
				for (int k = 0; k < 4; k ++) {
					ok2[k] = false;
					for (int l = 0; l < 4; l ++) {
						ok2[k] = ok2[k] || (ok[l] && G[l][k]);
					}
				}
				for (int k = 0; k < 4; k ++) ok[k] = ok2[k];
			}
			did = true;
			break;
		}
		if (!did) {
			puts("No");
			return 0;
		}
	}
	if (ok[0] || ok[1] || ok[2] || ok[3]) {
		puts("Yes");
	} else {
		puts("No");
	}
}