#include <bits/stdc++.h>
using namespace std;

using Int = long long;
const char newl = '\n';

template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}
template<typename T> void drop(const T &x){cout<<x<<endl;exit(0);}
template<typename T=int>
vector<T> read(size_t n){
  vector<T> ts(n);
  for(size_t i=0;i<n;i++) cin>>ts[i];
  return ts;
}


template<typename T, T MOD = 1000000007>
struct Mint{
  static constexpr T mod = MOD;
  T v;
  Mint():v(0){}
  Mint(signed v):v(v){}
  Mint(long long t){v=t%MOD;if(v<0) v+=MOD;}

  Mint pow(long long k){
    Mint res(1),tmp(v);
    while(k){
      if(k&1) res*=tmp;
      tmp*=tmp;
      k>>=1;
    }
    return res;
  }

  static Mint add_identity(){return Mint(0);}
  static Mint mul_identity(){return Mint(1);}

  Mint inv(){return pow(MOD-2);}

  Mint& operator+=(Mint a){v+=a.v;if(v>=MOD)v-=MOD;return *this;}
  Mint& operator-=(Mint a){v+=MOD-a.v;if(v>=MOD)v-=MOD;return *this;}
  Mint& operator*=(Mint a){v=1LL*v*a.v%MOD;return *this;}
  Mint& operator/=(Mint a){return (*this)*=a.inv();}

  Mint operator+(Mint a) const{return Mint(v)+=a;}
  Mint operator-(Mint a) const{return Mint(v)-=a;}
  Mint operator*(Mint a) const{return Mint(v)*=a;}
  Mint operator/(Mint a) const{return Mint(v)/=a;}

  Mint operator-() const{return v?Mint(MOD-v):Mint(v);}

  bool operator==(const Mint a)const{return v==a.v;}
  bool operator!=(const Mint a)const{return v!=a.v;}
  bool operator <(const Mint a)const{return v <a.v;}

  static Mint comb(long long n,int k){
    Mint num(1),dom(1);
    for(int i=0;i<k;i++){
      num*=Mint(n-i);
      dom*=Mint(i+1);
    }
    return num/dom;
  }
};
template<typename T, T MOD> constexpr T Mint<T, MOD>::mod;
template<typename T, T MOD>
ostream& operator<<(ostream &os,Mint<T, MOD> m){os<<m.v;return os;}


template<typename V>
V compress(V vs){
  sort(vs.begin(),vs.end());
  vs.erase(unique(vs.begin(),vs.end()),vs.end());
  return vs;
}
template<typename T>
map<T, int> dict(const vector<T> &vs){
  map<T, int> res;
  for(int i=0;i<(int)vs.size();i++)
    res[vs[i]]=i;
  return res;
}
map<char, int> dict(const string &s){
  return dict(vector<char>(s.begin(),s.end()));
}


struct UnionFind{
  int num;
  vector<int> rs,ps;
  UnionFind(int n):num(n),rs(n,1),ps(n,0){
    iota(ps.begin(),ps.end(),0);
  }
  int find(int x){
    return (x==ps[x]?x:ps[x]=find(ps[x]));
  }
  bool same(int x,int y){
    return find(x)==find(y);
  }
  void unite(int x,int y){
    x=find(x);y=find(y);
    if(x==y) return;
    if(rs[x]<rs[y]) swap(x,y);
    rs[x]+=rs[y];
    ps[y]=x;
    num--;
  }
  int size(int x){
    return rs[find(x)];
  }
  int count() const{
    return num;
  }
};

//INSERT ABOVE HERE
signed main(){
  cin.tie(0);
  ios::sync_with_stdio(0);

  int n,k;
  cin>>n>>k;
  vector<int> as(n),bs(n);
  for(int i=0;i<n;i++) cin>>as[i]>>bs[i],as[i]--,bs[i]--;

  using M = Mint<int, 998244353>;
  M ans{0};
  map<pair<int, int>, int> cnt;
  for(int bit=0;bit<(1<<n);bit++){
    vector<int> vs,deg(n);
    UnionFind uf(n);
    for(int i=0;i<n;i++){
      if((bit>>i)&1){
        uf.unite(as[i],bs[i]);
        deg[as[i]]++;
        deg[bs[i]]++;
        vs.emplace_back(as[i]);
        vs.emplace_back(bs[i]);
      }
    }
    vs=compress(vs);
    int valid=true;
    for(int v:vs)
      valid&=uf.same(vs[0],v);
    if(not valid) continue;
    int x=0,y=0;
    for(int v:vs){
      if(deg[v]==1) x++;
      if(deg[v]>=2) y++;
    }
    cnt[make_pair(x,y)]++;
    ans+=M(k).pow(x)*(M(1)-M(k)).pow(n-x-y)*M(x+y);
  }
  // for(auto[p,c]:cnt) cout<<p.first<<' '<<p.second<<':'<<c<<newl;
  ans+=M(n)*M(k).pow(1)*(M(1)-M(k)).pow(n-1-0)*M(1+0);
  cout<<ans<<newl;
  return 0;
}