// Skyqwq
#include <bits/stdc++.h>

#define pb push_back
#define fi first
#define se second
#define mp make_pair

using namespace std;

typedef long long LL;
typedef pair<int, int> PII;

template <typename T> bool chkMax(T &x, T y) { return (y > x) ? x = y, 1 : 0; }
template <typename T> bool chkMin(T &x, T y) { return (y < x) ? x = y, 1 : 0; }

template <typename T> void inline read(T &x) {
    int f = 1; x = 0; char s = getchar();
    while (s < '0' || s > '9') { if (s == '-') f = -1; s = getchar(); }
    while (s <= '9' && s >= '0') x = x * 10 + (s ^ 48), s = getchar();
    x *= f;
}

const int N = 5005, P = 998244353;

int m, n, f[N][N][3], sz[N], h[N][3], G[N], C[N][N], H[N], fact[N], infact[N], inv[N], F[N], B[N];

vector<int> g[N];

void inline clr() {
	for (int i = 1; i <= n; i++) g[i].clear();
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			f[i][j][0] = f[i][j][1] = f[i][j][2] = 0;
		}
	}
}

void inline add(int &x, int y) {
	x += y;
	if (x >= P) x -= P;
}

void merge(int u, int v) {
	int A = sz[u], B = sz[v], C = sz[u] + sz[v];
	for (int i = 1; i <= C; i++)
		h[i][0] = h[i][1] = h[i][2] = 0;
	for (int i = 1; i <= A; i++) {
		for (int j = 1; j <= B; j++) {
			for (int x = 0; x < 3; x++) {
				for (int y = 0; y < 3; y++) {
					add(h[i + j][x], 1ll * f[u][i][x] * f[v][j][y] % P * (y == 2 ? 2 : 1) % P);
					if (x >= 2 && y) add(h[i + j - 1][0], 1ll * f[u][i][x] * f[v][j][y] % P * 2 % P);
					if (x == 1 && y) add(h[i + j - 1][2], 1ll * f[u][i][x] * f[v][j][y] % P);
				}
			}
		}
	}
	
	for (int i = 1; i <= C; i++)
		f[u][i][0] = h[i][0], f[u][i][1] = h[i][1], f[u][i][2] = h[i][2];
	sz[u] += sz[v];
}

void dfs(int u, int la) {
	f[u][1][1] = 1;
	sz[u] = 1;
	for (int v: g[u]) {
		if (v == la) continue;
		dfs(v, u);
		merge(u, v);
	}
}

void inline prework() {
	inv[1] = 1;
	for (int i = 2; i < N; i++)
		inv[i] = (P - (LL)P / i) * inv[P % i] % P;
	fact[0] = infact[0] = 1;
	for (int i = 1; i < N; i++) {
		fact[i] = 1ll * fact[i - 1] * i % P;
		infact[i] = 1ll * infact[i - 1] * inv[i] % P;
	}
	C[0][0] = 1;
	for (int i = 1; i < N; i++) {
		C[i][0] = 1;
		for (int j = 1; j <= i; j++)
			C[i][j] = (C[i - 1][j] + C[i - 1][j - 1]) % P;
	}
}

int inline A(int x) {
	return (x & 1) ? P - 1 : 1;
}

int inline power(int a, int b) {
	int res = 1;
	while (b) {
		if (b & 1) res = 1ll * res * a % P;
		a = 1ll * a * a % P;
		b >>= 1;
	}
	return res;
}

int main() {
	prework();
	read(m);
	F[0] = 1;
	int S = 0;
	while (m--) {
		read(n);
		for (int i = 1, u, v; i < n; i++)
			read(u), read(v), g[u].pb(v), g[v].pb(u);
		dfs(1, 0);		
		for (int i = 1; i <= n; i++) G[i] = 0, H[i] = 0;
		for (int i = 1; i <= n; i++) {
			add(G[i], f[1][i][0]);
			add(G[i], f[1][i][1]);
			add(G[i], 1ll * f[1][i][2] * 2 % P);
		}
		for (int i = 1; i <= n; i++) {
			for (int j = i; j <= n; j++) {
				add(H[i], 1ll * G[j] * fact[j] % P * C[j - 1][j - i] % P * A(j - i) % P);
			}
		}
		for (int i = 0; i <= S; i++) B[i] = F[i], F[i] = 0;
		for (int i = 0; i <= S; i++) {
			for (int j = 1; j <= n; j++) {
				add(F[i + j], 1ll * B[i] * H[j] % P * infact[j] % P);
			}
		}
		S += n;
		clr();
	}
	int ans = 0;
	for (int i = 1; i <= S; i++) add(ans, 1ll * F[i] * fact[i - 1] % P);
	printf("%d\n", ans);
    return 0;
}