#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using mint = atcoder::modint998244353;
int main () {
	int N, M;
	cin >> N >> M;
	string s;
	cin >> s;
	std::vector<vector<int>> gr(N);
	for (int i = 0; i < M; i ++) {
		int a, b;
		cin >> a >> b;
		gr[--a].push_back(--b);
		gr[b].push_back(a);
	}
	mint ans = 0;
	for (int i = 0; i < N; i ++) {
		mint ca = 0, ci = 0, ch = 0;
		if ((s[i] != 'o') && (s[i] != '?')) continue;
		for (auto& j : gr[i]) {
			if (s[j] == 'a') {
				ca ++;
			} else if (s[j] == 'i') {
				ci ++;
			} else if (s[j] == '?') {
				ch ++;
			}
		}
		ans += ca * ci + ca * ch + ch * ci + (ch * (ch - 1));
	}
	cout << ans.val() << endl;
}