#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define fi first
#define se second
#define vi vector<int>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define vl vector<ll>
int n, m;
const int MN = 21, MS = (1<<18)+7, MOD = 998244353;
bool adj[MN][MN], f[MS]; //f[s]: whether s is an independent set
ll dp[MS]; //dp[s]: number of DAGs that can be formed by the points in s
int bits(int x) {return __builtin_popcount(x);}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> m;
for(int i = 1; i <= m; i++) {
int u, v; cin >> u >> v;
adj[u][v] = adj[v][u] = true; //ignore direction here
}
for(int i = 0; i < n; i++) dp[1<<i] = 1, f[1<<i] = true;
for(int s = 1; s < 1<<n; s++) {
if(bits(s)==1) continue;
int lb = s&(-s), llb = (s^lb)&(-(s^lb));
f[s] = f[s^lb] && f[s^llb] && !adj[(int)log2(lb)+1][(int)log2(llb)+1];
}
dp[0] = 1;
for(int s = 1; s < 1<<n; s++) {
if(bits(s)==1) continue;
for(int ss = s; ss > 0; ss=(ss-1)&s) {
if(!f[ss]) continue;
ll d = dp[s^ss];
if(bits(ss)%2==0) d *= -1;
dp[s] = (dp[s]+d+MOD)%MOD;
}
}
cout << dp[(1<<n)-1]*(MOD+1)/2%MOD*m%MOD << '\n';
}
