import java.io.*;
import java.util.*;
public class amusementpark {
public static int mod = 998244353;
public static void main(String[] args) throws IOException {
BufferedReader scan = new BufferedReader(new InputStreamReader(System.in));
StringTokenizer l1 = new StringTokenizer(scan.readLine());
int num = Integer.parseInt(l1.nextToken()); int m = Integer.parseInt(l1.nextToken());
HashMap<Integer, ArrayList<Integer>> graph = new HashMap<>();
for (int i = 0;i<num;i++) graph.put(i,new ArrayList<>());
for (int i = 0;i<m;i++) {
StringTokenizer st = new StringTokenizer(scan.readLine());
int a = Integer.parseInt(st.nextToken())-1; int b = Integer.parseInt(st.nextToken())-1;
graph.get(a).add(b);
}
//Store if a set i of vertices is independent or not
ArrayList<Integer> indep = new ArrayList<>();
for (int i = 0;i<(1<<num);i++) {
boolean temp = true;
for (int j = 0;j<num;j++) {
if ((i&(1<<j))==0) continue;
for (int k : graph.get(j)) {
if ((i&(1<<k))!=0){
temp = false; break;
}
}
if (!temp) break;
}
if (temp) indep.add(i);
}
//Use DP to count the number of DAGs in the given graph
long[] dp = new long[1<<num]; //Number of DAGs in the subgraph on the set i of vertices
dp[0] = 1;
for (int i = 1;i<(1<<num);i++) {
for (int j : indep) {
if ((i|j)!=i) continue; //Ensures j is a subset of i
int prev = i-j;
dp[i] = (dp[i]+(int) Math.pow(-1,Integer.bitCount(j)+1)*dp[prev])%mod;
dp[i] = (dp[i]+mod)%mod;
}
}
long ans = (dp[(1<<num)-1]*m)%mod;
ans = (ans%2==0) ? ans/2 : (ans+mod)/2;
System.out.println(ans);
}
}
