func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAXN = (1 << 19) + 5;   template <typename T>   inline void read(T &WOW) {     T x = 0, flag = 1;     char ch = getchar();     while (!isdigit(ch)) {       if (ch ==  - ) flag = -1;       ch = getchar();     }     while (isdigit(ch)) {       x = x * 10 + ch -  0 ;       ch = getchar();     }     WOW = flag * x;   }   namespace ModCalculator {   const int MOD = 998244353;   inline void Inc(int &x, int y) {     x += y;     if (x >= MOD) x -= MOD;   }   inline void Dec(int &x, int y) {     x -= y;     if (x < 0) x += MOD;   }   inline int Add(int x, int y) {     Inc(x, y);     return x;   }   inline int Sub(int x, int y) {     Dec(x, y);     return x;   }   inline int Mul(int x, int y) { return 1LL * x * y % MOD; }   inline int Ksm(int x, int y) {     int ret = 1;     for (; y; y >>= 1) {       if (y & 1) ret = Mul(ret, x);       x = Mul(x, x);     }     return ret;   }   inline int Inv(int x) { return Ksm(x, MOD - 2); }   }  // namespace ModCalculator   using namespace ModCalculator;   int len, rev[MAXN], w1[MAXN], w2[MAXN], fac[MAXN];   void NTT_init(int n) {     for (len = 1; len < n; len <<= 1)       ;     fac[0] = 1;     for (int i = 1; i <= len; ++i) {       fac[i] = Mul(fac[i - 1], i);     }     int Gi = 3, Gv = Inv(Gi);     for (int i = 1; i < len; i <<= 1) {       int wk1 = Ksm(Gi, (MOD - 1) / (i << 1)), wnk1 = 1;       int wk2 = Ksm(Gv, (MOD - 1) / (i << 1)), wnk2 = 1;       for (int k = 0; k < i; ++k) {         w1[i + k] = wnk1;         wnk1 = Mul(wnk1, wk1);         w2[i + k] = wnk2;         wnk2 = Mul(wnk2, wk2);       }     }   }   void GetRev(int n) {     int bit = -1;     for (len = 1; len < n; len <<= 1) ++bit;     for (int i = 0; i < len; ++i) {       rev[i] = (rev[i >> 1] >> 1) | ((i & 1) << bit);     }   }   void NTT(vector<int> &a, int type) {     a.resize(len);     int *w = (type == 1 ? w1 : w2);     for (int i = 0; i < len; ++i) {       if (i < rev[i]) {         swap(a[i], a[rev[i]]);       }     }     for (int i = 1; i < len; i <<= 1) {       for (int j = 0; j < len; j += (i << 1)) {         for (int k = 0; k < i; ++k) {           int x = a[j + k], y = Mul(a[j + k + i], w[i + k]);           a[j + k] = Add(x, y);           a[j + k + i] = Sub(x, y);         }       }     }     if (type == 1) return;     int lenv = Inv(len);     for (int i = 0; i < len; ++i) {       a[i] = Mul(a[i], lenv);     }   }   vector<int> Poly_Mul(vector<int> F, vector<int> G) {     int deg = F.size() + G.size() - 1;     if (deg <= 100) {       vector<int> H(deg, 0);       int n = F.size(), m = G.size();       for (int i = 0; i < n; ++i) {         for (int j = 0; j < m; ++j) {           Inc(H[i + j], Mul(F[i], G[j]));         }       }       return H;     }     GetRev(deg);     NTT(F, 1);     NTT(G, 1);     for (int i = 0; i < len; ++i) {       F[i] = Mul(F[i], G[i]);     }     NTT(F, -1);     F.resize(deg);     return F;   }   int n, deg[MAXN], node[MAXN], tot;   vector<int> Poly_Prod(int l, int r) {     if (l == r) {       vector<int> F;       F.push_back(1);       F.push_back(node[l]);       return F;     }     int mid = (l + r) >> 1;     return Poly_Mul(Poly_Prod(l, mid), Poly_Prod(mid + 1, r));   }   void solve() {     read(n);     NTT_init((n + 1) << 1);     for (int i = 1, u, v; i < n; ++i) {       read(u);       read(v);       ++deg[u];       ++deg[v];     }     for (int i = 1; i <= n; ++i) {       int x = deg[i] - (i > 1);       if (x) node[++tot] = x;     }     vector<int> F = Poly_Prod(1, tot);     int ans = 0;     for (int i = 0; i < n && i < F.size(); ++i) {       int tmp = Mul(F[i], fac[n - i]);       (i & 1) ? Dec(ans, tmp) : Inc(ans, tmp);     }     printf( %d n , ans);   }   int main() {     solve();     return 0;   }   