#include #include // cout, endl, cin #include // string, to_string, stoi #include // vector #include // min, max, swap, sort, reverse, lower_bound, upper_bound #include // pair, make_pair #include // tuple, make_tuple #include // int64_t, int*_t #include // printf #include // map #include // queue, priority_queue #include // set #include // stack #include // deque #include // unordered_map #include // unordered_set #include // bitset #include // isupper, islower, isdigit, toupper, tolower #include #include #include #include #include using namespace std; using namespace atcoder; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define repi(i, a, b) for (int i = (int)(a); i < (int)(b); i++) #define rep2(i, m, n) for (int i = (m); i < (n); ++i) #define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i) #define drep(i, n) drep2(i, n, 0) //#define endl '\n' #define all(x) (x).begin(),(x).end() #define arr(x) (x).rbegin(),(x).rend() typedef long long ll; typedef unsigned long long ull; const ll inf=1e18; //const int inf=1e7; using graph = vector > ; using P= pair; using vi=vector; using vvi=vector; using vll=vector; using vvll=vector; using vp=vector

; using vvp=vector; using vd=vector; using vvd =vector; //string T="ABCDEFGHIJKLMNOPQRSTUVWXYZ"; //string S="abcdefghijklmnopqrstuvwxyz"; //g++ main.cpp -std=c++17 -I . //cout < bool chmin(T& a, T b) { if (a > b) { a = b; return true; } else return false; } template bool chmax(T& a, T b) { if (a < b) { a = b; return true; } else return false; } struct edge{ int to; ll cost;int dir; edge(int to,ll cost,int dir) : to(to),cost(cost),dir(dir){} }; using ve=vector; using vve=vector; using mint = modint998244353; //using mint = modint1000000007; using vm=vector; using vvm=vector; const int mod = 998244353; //int mod = 1e9+7; constexpr ll MAX = 2001000; ll fact[MAX],finv[MAX],inv[MAX]; void initcomb(){ fact[0]=fact[1]=1; finv[0]=finv[1]=1; inv[1]=1; for(int i=2;i par, siz; UnionFind(int n) : par(n, -1) , siz(n, 1) { } int root(int x) { if (par[x] == -1) return x; else return par[x] = root(par[x]); } bool issame(int x, int y) { return root(x) == root(y); } bool unite(int x, int y) { x = root(x), y = root(y); if (x == y) return false; //if (siz[x] < siz[y]) swap(x, y); par[y] = x; siz[x] += siz[y]; return true; } int size(int x) { return siz[root(x)]; } }; struct Compress{ vll a; map d,d2; int cnt; Compress() :cnt(0) {} void add(ll x){a.push_back(x);} void init(){ sets(a.begin(),a.end()); for(auto y:s)d[y]=cnt++; for(auto&y:a)y=d[y]; for(auto u:d)d2[u.second]=u.first; } ll to(ll x){return d[x];} //変換先 ll from(ll x){return d2[x];}//逆引き int size(){return cnt;} }; vll anss; mint dp[31][17][100005]; void solve(int test){ initcomb(); int n,m; cin >> n >> m; vi a(m),b(m); rep(i,m)cin >> a[i] >> b[i],a[i]--,b[i]--; mint ans=0; for(int i=3; i<=n; i++){ mint now=comb(n,i); now*=fact[i-1]; now/=2; ans+=now; } rep(i,31)if(n-i>=0)dp[i][1][0]=1; rep(i,31)repi(j,1,17)rep(k,n+1){ mint now=dp[i][j][k]; if(!now.val())continue; if(j+1<=16)dp[i][j+1][k]+=now; if(k+1<=n-i)dp[i][j][k+1]+=now*(n-i-k); } rep(i,31)repi(j,1,17)repi(k,1,n+1)dp[i][j][k]+=dp[i][j][k-1]; repi(bit,1,1<>i&1){ deg[a[i]]++,deg[b[i]]++; if(uf.issame(a[i],b[i]))cnt++; uf.unite(a[i],b[i]); } int ok=1; rep(i,n)if(deg[i]>2)ok=0; if(!ok)continue; if(cnt){ int all=1; rep(i,n)if(deg[i]){ if(deg[i]!=2)all=0; } if(all && cnt==1){ if(__builtin_popcount(bit)%2)ans-=1; else ans+=1; continue; } else continue; } int num=0; int num2=0; rep(i,n)if(i==uf.root(i) && uf.size(i)>=2){ num++; num2+=uf.size(i); } if(num2>=3){ mint now=dp[num2][num][n-num2]; now*=pow_pow(2,num,mod); now*=fact[num-1]; now/=2; if(__builtin_popcount(bit)%2)ans-=now; else ans+=now; } else { mint now=dp[num2][num][n-num2]-1; now*=pow_pow(2,num,mod); now*=fact[num-1]; now/=2; if(__builtin_popcount(bit)%2)ans-=now; else ans+=now; } } cout << ans.val() << endl; } //g++ main.cpp -std=c++17 -I . int main(){cin.tie(0);ios::sync_with_stdio(false); int t=1;//cin >>t; rep(test,t)solve(test); for(auto ans:anss)cout << ans << endl; }