// #define NDEBUG
#include<bits/stdc++.h>
#define For(i,j,k) for(int i=(j);i<=(k);i++)
#define ForD(i,j,k) for(int i=(j);i>=(k);i--)
#define int long long
#define endl '\n'
using namespace std;
bool Mbe;
const int N=5e3+5,K=1e3+5,mod=998244353;
int qpow(int a,int b){
    int ans=1;
    while(b){
        if(b&1) ans=ans*a%mod;
        a=a*a%mod; b>>=1;
    }
    return ans;
}
int p,k,n;
#define pb push_back
struct Tree{
    vector<int> E[N];
    void in(){
        For(i,1,n-1){
            int u,v; cin>>u>>v;
            E[u].pb(v),E[v].pb(u);
        }
    }
}Tr[K];
void solve(){
    cin>>p>>k>>n;
    For(i,1,k) Tr[i].in();
    if(p==1){
        cout<<qpow(n,n-2)<<endl;
    }else{
        cout<<0<<endl;
    }
}
bool Med;
signed main(){
    fprintf(stderr,"%.3lf MB\n",(&Mbe-&Med)/1048576.0);
    // freopen("1.in","r",stdin), freopen("1.out","w",stdout);
    ios::sync_with_stdio(false); cin.tie(0),cout.tie(0);
    int _=1;
    cin>>_;
    while(_--) solve();
    cerr<<1e3*clock()/CLOCKS_PER_SEC<<" ms\n";
    return 0;
}