#include #define fi first #define se second #define rep(i,n) for(int i = 0; i < (n); ++i) #define rrep(i,n) for(int i = 1; i <= (n); ++i) #define drep(i,n) for(int i = (n)-1; i >= 0; --i) #define srep(i,s,t) for (int i = s; i < t; ++i) #define rng(a) a.begin(),a.end() #define rrng(a) a.rbegin(),a.rend() #define maxs(x,y) (x = max(x,y)) #define mins(x,y) (x = min(x,y)) #define isin(x,l,r) ((l) <= (x) && (x) < (r)) #define pb push_back #define eb emplace_back #define sz(x) (int)(x).size() #define pcnt __builtin_popcountll #define uni(x) x.erase(unique(rng(x)),x.end()) #define snuke srand((unsigned)clock()+(unsigned)time(NULL)); #define show(x) cout<<#x<<" = "< > #define bn(x) ((1< #define vv(T) v(v(T)) using namespace std; typedef long long int ll; typedef unsigned uint; typedef unsigned long long ull; typedef pair P; typedef tuple T; typedef vector vi; typedef vector vvi; typedef vector vl; typedef vector

vp; typedef vector vt; inline int getInt() { int x; scanf("%d",&x); return x;} templateinline istream& operator>>(istream&i,v(T)&v) {rep(j,sz(v))i>>v[j];return i;} templatestring join(const v(T)&v) {stringstream s;rep(i,sz(v))s<<' '<inline ostream& operator<<(ostream&o,const v(T)&v) {if(sz(v))o<inline istream& operator>>(istream&i,pair&v) {return i>>v.fi>>v.se;} templateinline ostream& operator<<(ostream&o,const pair&v) {return o<inline ll suma(const v(T)& a) { ll res(0); for (auto&& x : a) res += x; return res;} const double eps = 1e-10; const ll LINF = 1001002003004005006ll; const int INF = 1001001001; #define dame { puts("-1"); return 0;} #define yn {puts("Yes");}else{puts("No");} const int MX = 200005; // coordinate compression struct X { typedef int T; vector d; X() {} // X(vector& a): d(a) { // init(); // for (T& na : a) na = (*this)(na); // } void add(const T& x) { d.pb(x);} void init() { sort(rng(d)); d.erase(unique(rng(d)), d.end()); } int size() const { return sz(d);} T operator[](int i) const { return d[i];} int operator()(const T& x) const { return upper_bound(rng(d),x)-d.begin()-1;} }; // // Union find struct uf { vi d; uf(){} uf(int mx):d(mx,-1){} int root(int x) { if(d[x] < 0) return x; return d[x] = root(d[x]); } bool unite(int x, int y) { x = root(x); y = root(y); if(x == y) return false; if(d[x] > d[y]) swap(x,y); d[x] += d[y]; d[y] = x; return true; } bool same(int x, int y) { return root(x) == root(y);} int size(int x) { return -d[root(x)];} int operator[](int x) { return root(x);} int operator()(int x) { return size(x);} }; // // Mod int const int mod = 998244353; struct mint { ll x; mint():x(0){} mint(ll x):x((x%mod+mod)%mod){} // mint(ll x):x(x){} mint& fix() { x = (x%mod+mod)%mod; return *this;} mint operator-() const { return mint(0) - *this;} mint operator~() const { return mint(1) / *this;} mint& operator+=(const mint& a){ if((x+=a.x)>=mod) x-=mod; return *this;} mint& operator-=(const mint& a){ if((x+=mod-a.x)>=mod) x-=mod; return *this;} mint& operator*=(const mint& a){ (x*=a.x)%=mod; return *this;} mint& operator/=(const mint& a){ (x*=a.pow(mod-2).x)%=mod; return *this;} mint operator+(const mint& a)const{ return mint(*this) += a;} mint operator-(const mint& a)const{ return mint(*this) -= a;} mint operator*(const mint& a)const{ return mint(*this) *= a;} mint operator/(const mint& a)const{ return mint(*this) /= a;} mint pow(ll t) const { if(!t) return 1; mint res = pow(t/2); res *= res; return (t&1)?res*x:res; } bool operator<(const mint& a)const{ return x < a.x;} bool operator==(const mint& a)const{ return x == a.x;} }; mint ex(mint x, ll t) { return x.pow(t);} istream& operator>>(istream&i,mint&a){i>>a.x;return i;} ostream& operator<<(ostream&o,const mint&a){o< vm; struct comb { vm f, g; comb(){} comb(int mx):f(mx+1),g(mx+1) { f[0] = 1; rrep(i,mx) f[i] = f[i-1]*i; g[mx] = f[mx].pow(mod-2); for(int i=mx;i>0;i--) g[i-1] = g[i]*i; } mint operator()(int a, int b) { if (a < b) return 0; return f[a]*g[b]*g[a-b]; } } c(MX); // map mp; mint f(int n, int e) { P p(n,e); if (mp.count(p)) return mp[p]; mint res = 0; rep(i,n+1) res += c.f[n]*c.g[n-i]*c(i+e-1,e-1); // cerr<>j&1) { int a = es[j].fi, b = es[j].se; deg[a]++; deg[b]++; if (!t.unite(a,b)) ++cnt; if (deg[a] > 2) ok = false; if (deg[b] > 2) ok = false; } if (!ok) continue; int w = n-s, e = 0; rep(i,s) { if (t.root(i) != i) continue; if (t.size(i) == 1) ++w; else ++e; } if (cnt && e != 1) continue; mint now = 0; if (e) { now = c.f[e-1]*two[e-1]; now *= f(w,e); if (e == 1 && w == n-2) now -= 1; } else { srep(i,3,n+1) now += c(n,i)*c.f[i-1]*owt; } if (cnt) now = 1; // cout<