#include <bits/stdc++.h>
using namespace std;
#define int long long
const int mod = 998244353;
const int N = 1 << 18;
int dp[N], conn[18][18], sb[N];
bool indep[N];
int bm(int b, int p) {
if (!p) return 1;
int res = bm(b, p / 2);
res = res * res % mod;
if (p % 2 == 1) res = res * b % mod;
return res;
}
int32_t main() {
ios::sync_with_stdio(0); cin.tie(0);
int n, m;
cin >> n >> m;
for (int i = 1; i <= m; i++) {
int u, v;
cin >> u >> v;
--u, --v;
conn[u][v] = 1;
}
for (int i = 0; i < (1 << n); i++) {
indep[i] = 1;
for (int j = 0; j < n; j++) if ((1 << j) & i) sb[i]++;
sb[i]++;
for (int j = 0; j < n; j++) {
for (int k = 0; k < n; k++) {
if ((i & (1 << j)) && (i & (1 << k)) && conn[j][k]) {
indep[i] = 0;
break;
}
}
if (!indep[i]) break;
}
}
dp[0] = 1;
for (int i = 1; i < (1 << n); i++) {
for (int j = i; j; j = (j - 1) & i) {
if (indep[j]) (dp[i] += (dp[i ^ j] * ((sb[j] % 2 == 1) ? mod-1 : 1)) % mod) %= mod;
}
}
cout << dp[(1 << n) - 1] * m % mod * bm(2, mod-2) % mod << '\n';
}
