#include<bits/stdc++.h>
using namespace std;
const int MAXN=5005,MOD=998244353;
int fac[MAXN],ifac[MAXN];
int ksm(int a,int b=MOD-2,int p=MOD) {
	int ret=1;
	for(;b;a=1ll*a*a%p,b>>=1) if(b&1) ret=1ll*ret*a%p;
	return ret;
}
int C[MAXN][MAXN],co[MAXN][MAXN];
//co: i element -> j set
vector <int> G[MAXN];
int f[MAXN][MAXN],g[MAXN][MAXN],h[MAXN][MAXN]; //deg = 0,1,2
int tf[MAXN],tg[MAXN],th[MAXN],siz[MAXN];
void dfs(int u,int fz) {
	f[u][0]=1,siz[u]=1;
	for(int v:G[u]) if(v^fz) {
		dfs(v,u);
		memset(tf,0,sizeof(tf));
		memset(tg,0,sizeof(tg));
		memset(th,0,sizeof(th));
		for(int i=0;i<=siz[u];++i) for(int j=0;j<=siz[v];++j) {
			int x=(f[v][j]+2ll*g[v][j]+2ll*h[v][j])%MOD;
			tf[i+j+1]=(tf[i+j+1]+1ll*f[u][i]*x)%MOD;
			tg[i+j+1]=(tg[i+j+1]+1ll*g[u][i]*x)%MOD;
			th[i+j+1]=(th[i+j+1]+1ll*h[u][i]*x)%MOD;
			tg[i+j]=(tg[i+j]+1ll*f[u][i]*(f[v][j]+g[v][j]))%MOD;
			th[i+j]=(th[i+j]+1ll*g[u][i]*(f[v][j]+g[v][j]))%MOD;
		}
		siz[u]+=siz[v];
		memcpy(f[u],tf,sizeof(f[u]));
		memcpy(g[u],tg,sizeof(g[u]));
		memcpy(h[u],th,sizeof(h[u]));
	}
}
int wys[MAXN],dp[MAXN],tdp[MAXN]; //dp to i elements
signed main() {
	for(int i=fac[0]=1;i<MAXN;++i) ifac[i]=ksm(fac[i]=1ll*fac[i-1]*i%MOD)%MOD;
	for(int i=0;i<MAXN;++i) for(int j=C[i][0]=1;j<=i;++j) C[i][j]=(C[i-1][j]+C[i-1][j-1])%MOD;
	for(int i=1;i<MAXN;++i) for(int j=1;j<=i;++j) co[i][j]=1ll*fac[i]*ifac[j]%MOD*C[i-1][j-1]%MOD;
	int n,m,tot=0; dp[0]=1;
	scanf("%d",&m);
	for(int t=1;t<=m;++t) {
		scanf("%d",&n);
		for(int i=1;i<=n;++i) {
			G[i].clear(),siz[i]=0;
			memset(f[i],0,sizeof(f[i]));
			memset(g[i],0,sizeof(g[i]));
			memset(h[i],0,sizeof(h[i]));
		}
		for(int i=1,u,v;i<n;++i) {
			scanf("%d%d",&u,&v);
			G[u].push_back(v),G[v].push_back(u);
		}
		dfs(1,0);
		memset(wys,0,sizeof(wys));
		for(int i=1;i<=n;++i) {
			int v=(f[1][i-1]+2ll*g[1][i-1]+2ll*h[1][i-1])%MOD;
			for(int j=i;j>=1;--j) {
				wys[j]=(wys[j]+((i-j)&1?-1ll:1ll)*v*co[i][j])%MOD;
			}
		}
		for(int i=1;i<=n;++i) if(wys[i]<0) wys[i]+=MOD;
		memset(tdp,0,sizeof(tdp));
		for(int i=0;i<=tot;++i) for(int j=1;j<=n;++j) {
			tdp[i+j]=(tdp[i+j]+1ll*dp[i]*wys[j])%MOD;
		}
		tot+=n;
		memcpy(dp,tdp,sizeof(dp));
	}
	int ans=0;
	for(int i=1;i<=tot;++i) ans=(ans+1ll*dp[i]*fac[i-1])%MOD;
	printf("%d\n",ans);
	return 0;
}