import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] sa = br.readLine().split(" ");
		int n = Integer.parseInt(sa[0]);
		int m = Integer.parseInt(sa[1]);
		char[] s = br.readLine().toCharArray();
		List<List<Integer>> list = new ArrayList<>(n);
		for (int i = 0; i < n; i++) {
			list.add(new ArrayList<>());
		}
		for (int i = 0; i < m; i++) {
			sa = br.readLine().split(" ");
			int a = Integer.parseInt(sa[0]) - 1;
			int b = Integer.parseInt(sa[1]) - 1;
			list.get(a).add(b);
			list.get(b).add(a);
		}
		br.close();

		int mod = 998244353;
		int q = 0;
		long[] p = new long[n + 1];
		p[0] = 1;
		for (int i = 0; i < n; i++) {
			if (s[i] == '?') {
				q++;
				p[q] = p[q - 1] * 26 % mod;
			}
		}

		long ans = 0;
		for (int v1 = 0; v1 < n; v1++) {
			for (int v2 : list.get(v1)) {
				for (int v3 : list.get(v2)) {
					if (v1 != v2 && v2 != v3 && v3 != v1 &&
							(s[v1] == '?' || s[v1] == 'a') &&
							(s[v2] == '?' || s[v2] == 'o') &&
							(s[v3] == '?' || s[v3] == 'i')) {
						int c = 0;
						if (s[v1] == '?') c++;
						if (s[v2] == '?') c++;
						if (s[v3] == '?') c++;
						ans += p[q - c];
					}
				}
			}
		}
		ans %= mod;
		System.out.println(ans);
	}
}