#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using pl = pair<ll,ll>;
using pii = pair<int,int>;
using tpl = tuple<int,int,int>;
#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())
vector<int> adj[18];
vector<pii> dp[1 << 18];
int bitmask[18], good[1 << 18][18];
const int MOD = 998'244'353;
const int inv2 = 499'122'177;
int add (int a, int b) { return a + b - (a + b < MOD ? 0 : MOD); }
int sub (int a, int b) { return a - b + (a - b >= 0 ? 0 : MOD); }
int mul (int a, int b) { return 1LL * a * b % MOD; }
int binpow (int a, int b) {
int ans = 1;
for (; b; b >>= 1, a = mul(a, a))
if (b & 1) ans = mul(ans, a);
return ans;
}
bool getCur (int mask, int pos) {
return mask >> pos & 1;
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
int n, m; cin >> n >> m;
for (int i = 0; i < m; i++) {
int a, b; cin >> a >> b;
a--, b--;
adj[a].push_back(b);
adj[b].push_back(a);
bitmask[a] |= (1 << b);
bitmask[b] |= (1 << a);
}
for (int i = 0; i < n; i++)
sort(all(adj[i]), greater<int>());
/// find valid masks & setup mask case
for (int mask = 0; mask < (1 << n); mask++) {
bool valid = 1;
for (int i = 0; i < n; i++)
if (getCur(mask, i) && (mask & bitmask[i])) { valid = 0; break; }
if (valid) dp[0].emplace_back(mask, 1);
}
for (int mask = 0; mask < (1 << n); mask++) {
for (int i = 0; i < n; i++) {
int cur = 0;
for (int j : adj[i])
if (!(mask & bitmask[j])) cur |= (1 << j);
good[mask][i] = cur;
}
}
/// run DP
int ans = 0;
for (int A = 0; A < (1 << n); A++) {
if (A) {
sort(all(dp[A]));
vector<pii> tmp;
for (auto [B, val] : dp[A]) {
if (tmp.size() && tmp.back().first == B)
tmp[tmp.size() - 1].second = add(tmp.back().second, val);
else tmp.emplace_back(B, val);
}
swap(dp[A], tmp);
}
for (auto [B, val] : dp[A]) {
// cout << "dp " << bitset<2>(A) << ", " << bitset<2>(B) << " " << val << endl;
for (int sub = B; sub; sub -= sub & (-sub)) {
int cur = __builtin_ctz(sub), subFull = (1 << (cur + 1)) - 1;
int leftNode = B ^ (B & subFull), newNode = bitmask[cur] ^ (bitmask[cur] & (A | (1 << cur)));
dp[A | (1 << cur)].emplace_back(leftNode | newNode, val);
}
if (A == (1 << n) - 1 && B == 0) ans = val;
}
}
cout << mul(mul(ans, inv2), m);
return 0;
}
