#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using Int = long long; template ostream &operator<<(ostream &os, const pair &a) { return os << "(" << a.first << ", " << a.second << ")"; }; template ostream &operator<<(ostream &os, const vector &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; } template void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; } template bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; } template bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; } #define COLOR(s) ("\x1b[" s "m") //////////////////////////////////////////////////////////////////////////////// template struct ModInt { static constexpr unsigned M = M_; unsigned x; constexpr ModInt() : x(0U) {} constexpr ModInt(unsigned x_) : x(x_ % M) {} constexpr ModInt(unsigned long long x_) : x(x_ % M) {} constexpr ModInt(int x_) : x(((x_ %= static_cast(M)) < 0) ? (x_ + static_cast(M)) : x_) {} constexpr ModInt(long long x_) : x(((x_ %= static_cast(M)) < 0) ? (x_ + static_cast(M)) : x_) {} ModInt &operator+=(const ModInt &a) { x = ((x += a.x) >= M) ? (x - M) : x; return *this; } ModInt &operator-=(const ModInt &a) { x = ((x -= a.x) >= M) ? (x + M) : x; return *this; } ModInt &operator*=(const ModInt &a) { x = (static_cast(x) * a.x) % M; return *this; } ModInt &operator/=(const ModInt &a) { return (*this *= a.inv()); } ModInt pow(long long e) const { if (e < 0) return inv().pow(-e); ModInt a = *this, b = 1U; for (; e; e >>= 1) { if (e & 1) b *= a; a *= a; } return b; } ModInt inv() const { unsigned a = M, b = x; int y = 0, z = 1; for (; b; ) { const unsigned q = a / b; const unsigned c = a - q * b; a = b; b = c; const int w = y - static_cast(q) * z; y = z; z = w; } assert(a == 1U); return ModInt(y); } ModInt operator+() const { return *this; } ModInt operator-() const { ModInt a; a.x = x ? (M - x) : 0U; return a; } ModInt operator+(const ModInt &a) const { return (ModInt(*this) += a); } ModInt operator-(const ModInt &a) const { return (ModInt(*this) -= a); } ModInt operator*(const ModInt &a) const { return (ModInt(*this) *= a); } ModInt operator/(const ModInt &a) const { return (ModInt(*this) /= a); } template friend ModInt operator+(T a, const ModInt &b) { return (ModInt(a) += b); } template friend ModInt operator-(T a, const ModInt &b) { return (ModInt(a) -= b); } template friend ModInt operator*(T a, const ModInt &b) { return (ModInt(a) *= b); } template friend ModInt operator/(T a, const ModInt &b) { return (ModInt(a) /= b); } explicit operator bool() const { return x; } bool operator==(const ModInt &a) const { return (x == a.x); } bool operator!=(const ModInt &a) const { return (x != a.x); } friend std::ostream &operator<<(std::ostream &os, const ModInt &a) { return os << a.x; } }; //////////////////////////////////////////////////////////////////////////////// constexpr unsigned MO = 998244353; using Mint = ModInt; // det(a) // O(n^3) // Call by value: Modifies a (Watch out when using C-style array!) template T det(vector> a) { const int n = a.size(); T prod = 1; for (int h = 0; h < n; ++h) { for (int i = h; i < n; ++i) if (a[i][h]) { if (h != i) { prod = -prod; swap(a[h], a[i]); } break; } if (!a[h][h]) return 0; prod *= a[h][h]; const T s = a[h][h].inv(); for (int j = h + 1; j < n; ++j) a[h][j] *= s; for (int i = h + 1; i < n; ++i) { const T t = a[i][h]; if (t) for (int j = h + 1; j < n; ++j) a[i][j] -= t * a[h][j]; } } return prod; } int K; vector N, M; vector> A, B; int main() { for (; ~scanf("%d", &K); ) { N.resize(K); M.resize(K); A.resize(K); B.resize(K); for (int k = 0; k < K; ++k) { scanf("%d%d", &N[k], &M[k]); A[k].resize(M[k]); B[k].resize(M[k]); for (int i = 0; i < M[k]; ++i) { scanf("%d%d", &A[k][i], &B[k][i]); --A[k][i]; --B[k][i]; } } vector dp(K + 1, 0); dp[0] += 1; for (int k = 0; k < K; ++k) { Mint fs[2]; { vector> mat(N[k], vector(N[k], 0)); for (int i = 0; i < M[k]; ++i) { const int u = A[k][i]; const int v = B[k][i]; mat[u][u] += 1; mat[u][v] -= 1; mat[v][u] -= 1; mat[v][v] += 1; } mat.pop_back(); for (auto &row : mat) row.pop_back(); fs[0] = det(mat); } { vector> mat(N[k] - 1, vector(N[k] - 1, 0)); for (int i = 0; i < M[k]; ++i) { const int u = max(A[k][i] - 1, 0); const int v = max(B[k][i] - 1, 0); mat[u][u] += 1; mat[u][v] -= 1; mat[v][u] -= 1; mat[v][v] += 1; } mat.pop_back(); for (auto &row : mat) row.pop_back(); fs[1] = det(mat); } cerr<= 0; --l) { dp[l + 1] += dp[l] * fs[1]; dp[l] *= fs[0]; } } cerr<<"dp = "<