// #define _GLIBCXX_DEBUG #pragma GCC optimize("O2,no-stack-protector,unroll-loops,fast-math") #include using namespace std; #define rep(i, n) for (int i = 0; i < int(n); i++) #define per(i, n) for (int i = (n)-1; 0 <= i; i--) #define rep2(i, l, r) for (int i = (l); i < int(r); i++) #define per2(i, l, r) for (int i = (r)-1; int(l) <= i; i--) #define each(e, v) for (auto& e : v) #define MM << " " << #define pb push_back #define eb emplace_back #define all(x) begin(x), end(x) #define rall(x) rbegin(x), rend(x) #define sz(x) (int)x.size() template void print(const vector& v, T x = 0) { int n = v.size(); for (int i = 0; i < n; i++) cout << v[i] + x << (i == n - 1 ? '\n' : ' '); if (v.empty()) cout << '\n'; } using ll = long long; using pii = pair; using pll = pair; template bool chmax(T& x, const T& y) { return (x < y) ? (x = y, true) : false; } template bool chmin(T& x, const T& y) { return (x > y) ? (x = y, true) : false; } template using minheap = std::priority_queue, std::greater>; template using maxheap = std::priority_queue; template int lb(const vector& v, T x) { return lower_bound(begin(v), end(v), x) - begin(v); } template int ub(const vector& v, T x) { return upper_bound(begin(v), end(v), x) - begin(v); } template void rearrange(vector& v) { sort(begin(v), end(v)); v.erase(unique(begin(v), end(v)), end(v)); } // __int128_t gcd(__int128_t a, __int128_t b) { // if (a == 0) // return b; // if (b == 0) // return a; // __int128_t cnt = a % b; // while (cnt != 0) { // a = b; // b = cnt; // cnt = a % b; // } // return b; // } struct Union_Find_Tree { vector data; const int n; int cnt; Union_Find_Tree(int n) : data(n, -1), n(n), cnt(n) {} int root(int x) { if (data[x] < 0) return x; return data[x] = root(data[x]); } int operator[](int i) { return root(i); } bool unite(int x, int y) { x = root(x), y = root(y); if (x == y) return false; if (data[x] > data[y]) swap(x, y); data[x] += data[y], data[y] = x; cnt--; return true; } int size(int x) { return -data[root(x)]; } int count() { return cnt; }; bool same(int x, int y) { return root(x) == root(y); } void clear() { cnt = n; fill(begin(data), end(data), -1); } }; template struct Mod_Int { int x; Mod_Int() : x(0) {} Mod_Int(long long y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {} static int get_mod() { return mod; } Mod_Int& operator+=(const Mod_Int& p) { if ((x += p.x) >= mod) x -= mod; return *this; } Mod_Int& operator-=(const Mod_Int& p) { if ((x += mod - p.x) >= mod) x -= mod; return *this; } Mod_Int& operator*=(const Mod_Int& p) { x = (int)(1LL * x * p.x % mod); return *this; } Mod_Int& operator/=(const Mod_Int& p) { *this *= p.inverse(); return *this; } Mod_Int& operator++() { return *this += Mod_Int(1); } Mod_Int operator++(int) { Mod_Int tmp = *this; ++*this; return tmp; } Mod_Int& operator--() { return *this -= Mod_Int(1); } Mod_Int operator--(int) { Mod_Int tmp = *this; --*this; return tmp; } Mod_Int operator-() const { return Mod_Int(-x); } Mod_Int operator+(const Mod_Int& p) const { return Mod_Int(*this) += p; } Mod_Int operator-(const Mod_Int& p) const { return Mod_Int(*this) -= p; } Mod_Int operator*(const Mod_Int& p) const { return Mod_Int(*this) *= p; } Mod_Int operator/(const Mod_Int& p) const { return Mod_Int(*this) /= p; } bool operator==(const Mod_Int& p) const { return x == p.x; } bool operator!=(const Mod_Int& p) const { return x != p.x; } Mod_Int inverse() const { assert(*this != Mod_Int(0)); return pow(mod - 2); } Mod_Int pow(long long k) const { Mod_Int now = *this, ret = 1; for (; k > 0; k >>= 1, now *= now) { if (k & 1) ret *= now; } return ret; } friend ostream& operator<<(ostream& os, const Mod_Int& p) { return os << p.x; } friend istream& operator>>(istream& is, Mod_Int& p) { long long a; is >> a; p = Mod_Int(a); return is; } }; ll mpow2(ll x, ll n, ll mod) { ll ans = 1; x %= mod; while (n != 0) { if (n & 1) ans = ans * x % mod; x = x * x % mod; n = n >> 1; } ans %= mod; return ans; } template T modinv(T a, const T& m) { T b = m, u = 1, v = 0; while (b > 0) { T t = a / b; swap(a -= t * b, b); swap(u -= t * v, v); } return u >= 0 ? u % m : (m - (-u) % m) % m; } ll divide_int(ll a, ll b) { if (b < 0) a = -a, b = -b; return (a >= 0 ? a / b : (a - b + 1) / b); } // const int MOD = 1000000007; const int MOD = 998244353; using mint = Mod_Int; // ----- library ------- template void fast_zeta_transform(vector &a, bool upper) { int n = a.size(); assert((n & (n - 1)) == 0); for (int i = 1; i < n; i <<= 1) { for (int j = 0; j < n; j++) { if (!(j & i)) { if (upper) { a[j] += a[j | i]; } else { a[j | i] += a[j]; } } } } } template void fast_mobius_transform(vector &a, bool upper) { int n = a.size(); assert((n & (n - 1)) == 0); for (int i = 1; i < n; i <<= 1) { for (int j = 0; j < n; j++) { if (!(j & i)) { if (upper) { a[j] -= a[j | i]; } else { a[j | i] -= a[j]; } } } } } template vector subset_convolve(const vector &a, const vector &b) { int n = a.size(); assert((int)b.size() == n && (n & (n - 1)) == 0); int k = __builtin_ctz(n); vector> A(k + 1, vector(n, 0)), B(k + 1, vector(n, 0)), C(k + 1, vector(n, 0)); for (int i = 0; i < n; i++) { int t = __builtin_popcount(i); A[t][i] = a[i], B[t][i] = b[i]; } for (int i = 0; i <= k; i++) fast_zeta_transform(A[i], false), fast_zeta_transform(B[i], false); for (int i = 0; i <= k; i++) { for (int j = 0; j <= k - i; j++) { for (int l = 0; l < n; l++) C[i + j][l] += A[i][l] * B[j][l]; } } for (int i = 0; i <= k; i++) fast_mobius_transform(C[i], false); vector c(n); for (int i = 0; i < n; i++) c[i] = C[__builtin_popcount(i)][i]; return c; } template vector exp_of_set_power_series(const vector &a) { int n = a.size(); assert((n & (n - 1)) == 0 && a[0] == 0); vector ret(n, 0); ret[0] = 1; for (int i = 1; i < n; i <<= 1) { vector f(begin(a) + i, begin(a) + (i << 1)); vector g(begin(ret), begin(ret) + i); auto h = subset_convolve(f, g); copy(begin(h), end(h), begin(ret) + i); } return ret; } // ----- library ------- int main() { ios::sync_with_stdio(false); std::cin.tie(nullptr); cout << fixed << setprecision(15); int n, m; cin >> n >> m; vector> g(n, vector(n, 0)); rep(i, m) { int u, v; cin >> u >> v; u--, v--; g[u][v] = 1, g[v][u] = 1; } vector> dp(1 << n, vector(n, 0)); rep(i, n) dp[1 << i][i] = 1; rep2(i, 1, 1 << n) { int s = __builtin_ctz(i); rep(j, n) rep2(k, s + 1, n) if (!(i & (1 << k)) && g[j][k]) dp[i | (1 << k)][k] += dp[i][j]; } vector c(1 << n); rep2(i, 1, 1 << n) { int k = __builtin_popcount(i); if (k == 1) { c[i] = 1; continue; } if (k == 2) { c[i] = 0; continue; } c[i] = 0; int s = __builtin_ctz(i); rep(j, n) c[i] += dp[i][j] * g[s][j]; c[i] /= 2; } vector E(1 << n, 0); rep(i, 1 << n) rep(j, n) rep2(k, j + 1, n) if ((i & (1 << j)) && (i & (1 << k))) E[i] += g[j][k]; vector f(1 << n, 0); rep2(C, 1, 1 << n) { int m = 1; while (m <= C) m *= 2; int D = (m - 1) & ~C; vector g; for (int T = D;; T = (T - 1) & D) { g.eb(f[T] * (E[T | C] - E[T] - E[C])); if (T == 0) break; } reverse(all(g)); auto h = exp_of_set_power_series(g); f[C] += c[C]; for (int T = D, idx = sz(h) - 1; idx > 0; T = (T - 1) & D, idx--) f[C | T] += c[C] * h[idx]; } cout << exp_of_set_power_series(f).back() << endl; }