#include using namespace atcoder; #include using namespace internal; #include using namespace std; #include #pragma GCC target("avx2") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define rep2(i,a,b) for (int i = (int)(a); i < (int)(b); i++) #define all(v) v.begin(),v.end() #define inc(x,l,r) ((l)<=(x)&&(x)<(r)) #define Unique(x) sort(all(x)), x.erase(unique(all(x)), x.end()) #define pcnt __builtin_popcountll typedef long long ll; #define int ll using ld = long double; using vi = vector; using vs = vector; using P = pair; using vp = vector

; using ull = unsigned long long; using Bint = boost::multiprecision::cpp_int; template bool chmax(T1 &a, const T2 b) {if (a < b) {a = b; return true;} else return false; } template bool chmin(T1 &a, const T2 b) {if (a > b) {a = b; return true;} else return false; } template using priority_queue_greater = priority_queue, greater>; template ostream &operator<< (ostream &os, const pair &p){os << p.first <<" "<> (istream &is, modint1000000007 &m){ll in;is>>in;m=in;return is;} ostream &operator<< (ostream &os, const modint998244353 &m){os << m.val();return os;} istream &operator>> (istream &is, modint998244353 &m){ll in;is>>in;m=in;return is;} template istream &operator>>(istream& is,vector &v){for(T &in:v)is>>in;return is;} template void input(T&... a){(cin>> ... >> a);} #ifdef LOCAL template ostream &operator<<(ostream &os,const vector &v){os<<"\x1b[32m";rep(i,v.size())os< int print(T& a){cout << "\x1b[32m"<< a<< '\n' << "\x1b[0m";return 0;} template int print(const T&a, const Ts&... b){cout << "\x1b[32m" << a;(cout<<...<<(cout<<' ',b));cout<<'\n' << "\x1b[0m";return 0;} #else template ostream &operator<<(ostream &os,const vector &v){rep(i,v.size())os< int print(T& a){cout << a<< '\n';return 0;} template int print(const T&a, const Ts&... b){cout << a;(cout<<...<<(cout<<' ',b));cout<<'\n';return 0;} #endif #define VI(v,n) vi v(n); input(v) #define INT(...) int __VA_ARGS__; input(__VA_ARGS__) #define STR(...) string __VA_ARGS__; input(__VA_ARGS__) #define CHAR(...) char __VA_ARGS__; input(__VA_ARGS__) int sign(ll x){return x>0?1:x<0?-1:0;} ll ceil(ll x,ll y){assert(y!=0);if(sign(x)==sign(y))return (x+y-1)/y;return -((-x/y));} ll floor(ll x,ll y){assert(y!=0);if(sign(x)==sign(y))return x/y;if(y<0)x*=-1,y*=-1;return x/y-(x%y<0);} ll abs(ll x,ll y){return abs(x-y);} ll bit(int n){return 1ll< bool ins(string s,T t){return s.find(t)!=string::npos;} P operator+ (const P &p, const P &q){ return P{p.first+q.first,p.second+q.second};} P operator- (const P &p, const P &q){ return P{p.first-q.first,p.second-q.second};} int yesno(bool ok,string y="Yes",string n="No"){ cout<<(ok?y:n)<struct edge{int to;T cost;int idx;}; templateclass Graph{ public: int n; bool weighted,directed; vector>> edges; vector>> E; Graph(int n,bool weighted=false,bool directed=false):n(n),weighted(weighted),directed(directed),E(n){} void add_edge(int u,int v,T w=1){ int idx = edges.size(); E[u].push_back({v,w,idx}); if(!directed)E[v].push_back({u,w,idx}); edges.push_back({u,{v,w,idx}}); } void read_edge(int m,int index=1){ rep(i,m){ int u,v; cin>>u>>v; u-=index,v-=index; if(weighted){ T w;cin>>w; add_edge(u,v,w); } else add_edge(u,v); } } inline const vector> &operator[](int u) const { return E[u]; } inline vector> &operator[](int u) { return E[u]; } pair> get_edge(int i){return edges[i];} vector namori(){ assert(n==edges.size()); vi deg(n); rep(u,n)for(auto &e:E[u])deg[e.to]++; vector is_cycle(n,true); queue Q; rep(u,n)if(deg[u]==1)Q.push(u); while(Q.size()){ auto u = Q.front();Q.pop(); is_cycle[u] = false; for(auto e:E[u]){ if(deg[e.to]>=2){ deg[e.to]--; if(deg[e.to]==1)Q.push(e.to); } } } return is_cycle; } }; signed main() { cin.tie(0); ios_base::sync_with_stdio(false); cout << fixed << setprecision(20); INT(n,k); Graph G(n); G.read_edge(n); auto l = G.namori(); int loop = 0; for(auto e:l)if(e)loop++; vector dp(2); dp[1] = k; rep(i,loop-1){ vector pd(2); rep(j,2){ pd[0] += dp[j]*(k-1-!j); pd[1] += dp[j]*(!j); } swap(dp,pd); } print(dp[0]*mint(k-1).pow(n-loop)); return 0; }