#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>

using namespace std;

const int N = 1e5 + 10;

inline int du(void) {
	int x = 0, f = 1;
	char ch = getchar();
	while (ch > '9' || ch < '0') { if (ch == '-')f = -1; ch = getchar(); }
	while (ch >= '0' && ch <= '9') { x = x * 10 + ch - '0'; ch = getchar(); }
	return x * f;
}
inline void write(int x) {
	if (x < 0) { putchar('-'); x = -x; }
	if (x > 9)write(x / 10);
	putchar(x % 10 ^ 48);
	return;
}

int k, n, m;

int head[N << 1], nx[N << 1], ver[N << 1], cnt;
inline void add(int x, int y) {
	ver[cnt] = y;
	nx[cnt] = head[x]; head[x] = cnt++;
	return;
}

int dfn[N << 1], low[N << 1], ti, top, st[N << 1], vis[N << 1], kind;
int co[N << 1];
inline void tarjan(int u) {
	dfn[u] = low[u] = ++ti;
	st[++top] = u, vis[u] = true;

	for (int i = head[u]; ~i; i = nx[i]) {
		int v = ver[i];
		if (!dfn[v]) {
			tarjan(v);
			low[u] = min(low[u], low[v]);
		}
		else if (vis[v]) low[u] = min(low[u], dfn[v]);
	}

	if (dfn[u] == low[u]) {
		int v;
		++kind;
		while ((v = st[top--]) != 0) {
			co[v] = kind;
			vis[v] = false;
			if (u == v)break;
		}
	}

	return;
}

int main(void) {

	ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);

	cin >> k;

	while (k--) {
		cin >> n >> m;

		memset(head, -1, sizeof(head));
		memset(nx, 0, sizeof(nx));
		memset(ver, 0, sizeof(ver));
		cnt = 0;

		while (m--) {
			string a, b;
			cin >> a >> b;
			int i, j, vi, vj;
			if (a[0] == 'm')vi = 0;
			if (a[0] == 'h')vi = 1;
			if (b[0] == 'm')vj = 0;
			if (b[0] == 'h')vj = 1;
			i = a[1] - '0';
			j = b[1] - '0';//坑点

			if (vi && vj) {
				add(i + n, j);
				add(j + n, i);
			}
			if (!vi && vj) {
				add(i, j);
				add(j + n, i + n);
			}
			if (vi && !vj) {
				add(i + n, j + n);
				add(j, i);
			}
			if (!vi && !vj) {
				add(i, j + n);
				add(j, i + n);
			}
		}

		memset(dfn, 0, sizeof(dfn));
		memset(low, 0, sizeof(low));
		memset(st, 0, sizeof(st));
		memset(vis, 0, sizeof(vis));
		memset(co, 0, sizeof(co));
		ti = top = kind = 0;

		for (int i = 1; i <= (n << 1); ++i) {
			if (!dfn[i])
				tarjan(i);
		}

		bool flag = true;

		for (int i = 1; i <= n; ++i) {
			if (co[i] == co[i + n]) {
				//cout << "BAD" << endl;
				flag = false;
				//break;	
			}
		}
		if (!flag)cout << "BAD" << endl;
		else if (flag)cout << "GOOD" << endl;

	}

	return 0;
}