// naive

#include<bits/stdc++.h>
using namespace std;
#include<atcoder/modint>
typedef atcoder::modint998244353 mint;

mint det(vector<vector<mint>> &a){
	assert(a.size() == a[0].size());
	int n = (int)a.size();
	vector<vector<mint>> b = a;
	int piv = 0;
	mint ret = 1;
	for (int j=0; j<n; j++){
		for (int i=piv; i<n; i++){
			if (b[i][j] != 0){
				swap(b[i], b[piv]);
				if (i != piv) ret = -ret;
				mint ip = b[piv][j].inv();
				for (int l=0; l<n; l++){
					if (l != piv){
						mint tmp = ip * b[l][j];
						for (int k=j; k<n; k++){
							b[l][k] -= tmp * b[piv][k];
						}
					}
				}
				ret *= b[piv][j];
				for (int k=j; k<n; k++){
					b[piv][k] *= ip;
				}
				piv++;
				break;
			}
		}
	}
	for (int i=0; i<n; i++){
		ret *= b[i][i];
	}
	return ret;
}

int main() {
	int k; cin >> k;
	
	vector dp(k+1, vector<mint>(2));
	dp[0][0] = 1;

	for(int i=0; i<k; i++) {
		int n, m; cin >> n >> m;
		vector mat1(n-1, vector<mint>(n-1));
		for (int i=0; i<m; i++) {
			int x, y; cin >> x >> y;
			x--; y--;
			if (x-1 >= 0 && y-1 >= 0) {
				mat1[x-1][y-1] -= 1;
				mat1[y-1][x-1] -= 1;
			}
			if (x-1 >= 0) {
				mat1[x-1][x-1] += 1;
			}
			if (y-1 >= 0) {
				mat1[y-1][y-1] += 1;
			}
		}
		vector<vector<mint>> mat2 = mat1;
		mat2[0][0] += 1;

		mint val1 = det(mat1);
		mint val2 = det(mat2);
		mint type123 = val1;
		mint type4 = val2 - val1;

		dp[i+1][1] += dp[i][0] * type123;
		dp[i+1][0] += dp[i][0] * (type123 * 2 + type4);
		dp[i+1][1] += dp[i][1] * (type123 * 2 + type4);
	}

	cout << dp[k][1].val() << endl;
	
}