#include using namespace std; using ll = long long; using ld = long double; using pll = pair; using tlll = tuple; constexpr ll INF = 1LL << 60; template bool chmin(T& a, T b) {if (a > b) {a = b; return true;} return false;} template bool chmax(T& a, T b) {if (a < b) {a = b; return true;} return false;} ll safemod(ll A, ll M) {ll res = A % M; if (res < 0) res += M; return res;} ll divfloor(ll A, ll B) {if (B < 0) A = -A, B = -B; return (A - safemod(A, B)) / B;} ll divceil(ll A, ll B) {if (B < 0) A = -A, B = -B; return divfloor(A + B - 1, B);} ll pow_ll(ll A, ll B) {if (A == 0 || A == 1) {return A;} if (A == -1) {return B & 1 ? -1 : 1;} ll res = 1; for (int i = 0; i < B; i++) {res *= A;} return res;} ll logfloor(ll A, ll B) {assert(A >= 2); ll res = 0; for (ll tmp = 1; tmp <= B / A; tmp *= A) {res++;} return res;} ll logceil(ll A, ll B) {assert(A >= 2); ll res = 0; for (ll tmp = 1; tmp < B; tmp *= A) {res++;} return res;} ll arisum_ll(ll a, ll d, ll n) { return n * a + (n & 1 ? ((n - 1) >> 1) * n : (n >> 1) * (n - 1)) * d; } ll arisum2_ll(ll a, ll l, ll n) { return n & 1 ? ((a + l) >> 1) * n : (n >> 1) * (a + l); } ll arisum3_ll(ll a, ll l, ll d) { assert((l - a) % d == 0); return arisum2_ll(a, l, (l - a) / d + 1); } template void unique(vector &V) {V.erase(unique(V.begin(), V.end()), V.end());} template void sortunique(vector &V) {sort(V.begin(), V.end()); V.erase(unique(V.begin(), V.end()), V.end());} #define FINALANS(A) do {cout << (A) << '\n'; exit(0);} while (false) template void printvec(const vector &V) {int _n = V.size(); for (int i = 0; i < _n; i++) cout << V[i] << (i == _n - 1 ? "" : " ");cout << '\n';} template void printvect(const vector &V) {for (auto v : V) cout << v << '\n';} template void printvec2(const vector> &V) {for (auto &v : V) printvec(v);} //* #include using namespace atcoder; using mint = modint998244353; //using mint = modint1000000007; //using mint = modint; //*/ template struct Matrix : vector> { using vector>::vector; using vector>::operator=; Matrix(int n, int m, T diag = 0, T non_diag = 0) { (*this) = vector>(n, vector(m, non_diag)); for (int i = 0; i < min(n, m); i++) (*this)[i][i] = diag; } Matrix operator-() const { int N = (*this).size(), M = (*this)[0].size(); Matrix res(*this); for (int i = 0; i < N; i++) for (int j = 0; j < M; j++) res[i][j] = -res[i][j]; return res; } Matrix &operator+=(const Matrix &A) { int N = (*this).size(), M = (*this)[0].size(); assert((int)A.size() == N && (int)A[0].size() == M); for (int i = 0; i < N; i++) for (int j = 0; j < M; j++) (*this)[i][j] += A[i][j]; return *this; } Matrix &operator-=(const Matrix &A) { int N = (*this).size(), M = (*this)[0].size(); assert((int)A.size() == N && (int)A[0].size() == M); for (int i = 0; i < N; i++) for (int j = 0; j < M; j++) (*this)[i][j] -= A[i][j]; return *this; } Matrix &operator*=(const T x) { int N = (*this).size(), M = (*this)[0].size(); for (int i = 0; i < N; i++) for (int j = 0; j < M; j++) (*this)[i][j] *= x; return *this; } Matrix &operator/=(const T x) { return (*this) *= (1 / x); } friend Matrix &operator*=(const T x, Matrix &A) { return A *= x; } vector operator*(const vector &v) const { int N = (*this).size(), M = (*this)[0].size(); assert((int)v.size() == M); vector res(N, T(0)); for (int i = 0; i < N; i++) for (int j = 0; j < M; j++) res[i] += (*this)[i][j] * v[j]; return res; } Matrix operator*(const Matrix &A) const { int N = (*this).size(), M = (*this)[0].size(); assert((int)A.size() == M); int K = A[0].size(); Matrix res(N, K, T(0)); for (int i = 0; i < N; i++) for (int j = 0; j < M; j++) for (int k = 0; k < K; k++) res[i][k] += (*this)[i][j] * A[j][k]; return res; } Matrix pow(ll k) const { int N = (*this).size(), M = (*this)[0].size(); assert(N == M); Matrix res(N, N, T(1)), tmp(*this); while (k > 0) { if (k & 1) res *= tmp; tmp *= tmp; k >>= 1; } return res; } Matrix operator+(const Matrix &A) const { return Matrix(*this) += A; } Matrix operator-(const Matrix &A) const { return Matrix(*this) -= A; } Matrix operator*(const T x) const { return Matrix(*this) *= x; } Matrix operator/(const T x) const { return Matrix(*this) /= x; } friend Matrix operator*(const T x, Matrix &A) { return matrix(A) *= x; } Matrix &operator*=(const Matrix &A) { return (*this) = (*this) * A; } T det() const { Matrix A(*this); int N = A.size(); assert((int)A[0].size() == N); T res = T(1); for (int i = 0; i < N; i++) { for (int k = i; k < N; k++) { if (A[k][i] != T(0)) { for (int l = k - 1; l >= i; l--) { swap(A[l], A[l + 1]); res = -res; } break; } } if (A[i][i] == T(0)) return T(0); res *= A[i][i]; T aii_inv = 1 / A[i][i]; for (int j = 0; j < N; j++) A[i][j] *= aii_inv; for (int k = i + 1; k < N; k++) { T aki = A[k][i]; for (int j = i; j < N; j++) A[k][j] -= A[i][j] * aki; } } return res; } Matrix inv() const // 存在しない場合空配列を返す { Matrix A(*this); int N = A.size(); assert((int)A[0].size() == N); Matrix B(N, N, T(1)); for (int i = 0; i < N; i++) { for (int k = i; k < N; k++) { if (A[k][i] != T(0)) { swap(A[k], A[i]); swap(B[k], B[i]); break; } } if (A[i][i] == T(0)) return Matrix(0, 0); T aii_inv = 1 / A[i][i]; for (int j = 0; j < N; j++) A[i][j] *= aii_inv, B[i][j] *= aii_inv; for (int k = 0; k < N; k++) { if (k == i) continue; T aki = A[k][i]; for (int j = 0; j < N; j++) { A[k][j] -= A[i][j] * aki; B[k][j] -= B[i][j] * aki; } } } //assert((*this) * B == matrix(N, N, T(1))); return B; } Matrix row_reduction() const { Matrix A(*this); int N = A.size(), M = A[0].size(); for (int i = 0, j = 0; i < N && j < M; j++) { for (int k = i; k < N; k++) { if (A[k][j] != T(0)) { swap(A[k], A[i]); break; } } if (A[i][j] == T(0)) continue; T aij_inv = 1 / A[i][j]; for (int l = 0; l < M; l++) A[i][l] *= aij_inv; for (int k = 0; k < N; k++) { if (k == i) continue; T akj = A[k][j]; for (int l = 0; l < M; l++) A[k][l] -= A[i][l] * akj; } i++; } return A; } // Ax = b を満たすベクトル x // 存在しなければ空 // 存在すれば, 0 番目に解の一つ, 1 番目以降に基底ベクトルが入ったものを返す vector> system(const vector &b) const { Matrix A(*this); int N = A.size(), M = A[0].size(); assert((int)b.size() == N); for (int i = 0; i < N; i++) A[i].emplace_back(b[i]); A = A.row_reduction(); vector pivot_i(M, -1), pivot_j(N, -1); vector sol(M, T(0)); for (int j = 0; j < M; j++) { int k = -1; for (int i = 0; i < N; i++) { if (A[i][j] != T(0)) { if (k == -1) k = i; else { k = -2; break; } } } if (k >= 0 && pivot_j[k] == -1) { pivot_j[k] = j, pivot_i[j] = k; sol[j] = A[k][M]; } } if ((*this) * sol != b) return vector>(); vector> basis; vector base; for (int j = 0; j < M; j++) { if (pivot_i[j] != -1) continue; base.assign(M, T(0)); base[j] = T(1); for (int i = 0; i < N; i++) { if (pivot_j[i] != -1) base[pivot_j[i]] = -A[i][j]; } basis.emplace_back(base); } basis.insert(basis.begin(), sol); return basis; } }; // https://yamate11.github.io/blog/posts/2021/04-18-kirchhoff/ // 自己ループのない無向グラフの全域木の個数を求める // G[i][j] は (i, j) 間を結ぶ辺の本数。G[i][j] = G[j][i] を満たす必要がある // G[i][i] = 0 のはずだが、そうでない入力に対しても G[i][i] = 0 とみなして計算する template T count_spanning_trees(const vector> &G) { using mat = Matrix; int n = G.size(); for (auto &a : G) assert((int)a.size() == n); if (n == 1) return 1; mat A(n - 1, n - 1, 0, 0); for (int i = 0; i < n - 1; i++) { for (int j = i + 1; j < n - 1; j++) { assert(G[i][j] == G[j][i]); A[i][j] = -G[i][j]; A[j][i] = -G[i][j]; A[i][i] += G[i][j]; A[j][j] += G[i][j]; } assert(G[i][n - 1] == G[n - 1][i]); A[i][i] += G[i][n - 1]; } return A.det(); } pair solve(ll N, ll M, vector &UV) { vector> G(N); dsu ds(N); for (auto [u, v] : UV) { G.at(u).push_back(v); G.at(v).push_back(u); ds.merge(u, v); } mint num = 1; if (ds.groups().size() == 1) { vector> H(N, vector(N, 0)); for (ll i = 0; i < N; i++) { for (auto j : G.at(i)) H.at(i).at(j)++; } num = count_spanning_trees(H); for (ll i = 0; i < M; i++) { vector UV2; dsu ds2(N); for (ll j = 0; j < M; j++) { if (i == j) continue; UV2.push_back(UV.at(j)); auto [u, v] = UV.at(j); ds2.merge(u, v); } if (ds2.groups().size() == 1) continue; num += solve(N, M, UV2).second - 1; } return {0, num}; } auto gs = ds.groups(); for (auto g : gs) { ll K = g.size(); vector> H(K, vector(K, 0)); vector inv(N); for (ll i = 0; i < K; i++) { inv.at(g.at(i)) = i; } for (ll i = 0; i < K; i++) { ll u = g.at(i); for (auto v : G.at(u)) { ll j = inv.at(v); H.at(i).at(j)++; } } mint tmp = count_spanning_trees(H); num *= tmp; } vector C; for (auto g : gs) C.push_back(g.size()); sort(C.begin(), C.end(), greater()); ll ans = 0; for (ll i = 0; i < N; i++) { for (ll j = 0; j < N; j++) { if (!ds.same(i, j)) ans++; } } if (C.size() >= 2) { ans -= C.at(0) * C.at(1); ans -= C.at(1) * C.at(0); while (C.size() > 2) { if (C.back() == C.front()) break; else C.pop_back(); } ll L = C.size(); num *= mint(L * (L - 1) / 2) * C.at(0) * C.at(1); } return {ans, num}; } int main() { ll N, M; cin >> N >> M; vector UV(M); for (ll i = 0; i < M; i++) { ll u, v; cin >> u >> v; u--, v--; UV.at(i) = {u, v}; } auto [ans, num] = solve(N, M, UV); cout << ans << endl << num.val() << endl; }