#include <bits/stdc++.h>
using namespace std;
#define MAXN 1000005

int t, n, m, k, vct, sct, cnt;
int dfn[MAXN], low[MAXN], scc[MAXN];
int val[MAXN]; bool vis[MAXN], ans[MAXN];
stack<int, list<int>> st;
vector<int> e[MAXN], g[MAXN];

void addeg(int u, int v){
	e[u].push_back(v);
	g[v].push_back(u);
	// cout << u << ' ' << v << '\n';
}

namespace Seg{
	int idx[MAXN], idy[MAXN];  // idx：进 idy：出
	void build(int p, int l, int r){
		if (l == r){idx[p]=idy[p]=l; return;}
		int mid((l+r)>>1); build(p<<1, l, mid); build(p<<1|1, mid+1, r);
		idx[p] = ++vct; idy[p] = ++vct;
		addeg(idx[p], idx[p<<1]); addeg(idx[p], idx[p<<1|1]);
		addeg(idy[p<<1], idy[p]); addeg(idy[p<<1|1], idy[p]);
	}
	void conct(int p, int l, int r, int L, int R, int x, bool opt){
		if (L <= l && r <= R){
			if (opt) addeg(idy[p], x);
			else addeg(x, idx[p]);
			return;
		}
		int mid((l+r)>>1);
		if (L <= mid) conct(p<<1, l, mid, L, R, x, opt);
		if (R > mid) conct(p<<1|1, mid+1, r, L, R, x, opt);
	}
}

void tarjan(int x){
	dfn[x] = low[x] = ++cnt;
	st.push(x); vis[x] = 1;
	for (auto i: e[x]){
		if (!dfn[i]){tarjan(i); low[x] = min(low[x], low[i]);}
		else if (vis[i]) low[x] = min(low[x], dfn[i]);
	}
	if (dfn[x] == low[x]){
		scc[x] = ++sct; vis[x] = 0;
		for (; st.top() ^ x; st.pop()){scc[st.top()] = sct; vis[st.top()] = 0;}
		st.pop();
	}
}

int dfs(int x, bool k){  // k = 1 搜前缀 k = 0 搜后缀
	if (ans[x]) return 0;
	ans[x] = 1; int sz(x <= n);
	if (!k) for (auto i: e[x]) sz += dfs(i, 0);
	else for (auto i: g[x]) sz += dfs(i, 1);
	return sz;
}

bool calc(){
	for (int i(1); i<=n; ++i) ++val[scc[i]];
	for (int i(1), res(0), ps(0); i<=sct; ++i){
		res += val[i];
		if (res > 2*k){
			for (int j(1); j<=n; ++j) if (scc[j] == i) ps = j;
			for (int j(1); j<=vct; ++j) ans[j] = 0;
			if (dfs(ps, 1) <= 2*k){
				for (int i(1); i<=n; ++i) ans[i] ^= 1;
				return true;
			}
			for (int i(1); i<=vct; ++i) ans[i] = 0;
			return dfs(ps, 0) <= 2*k;
		}else if (res >= k){
			for (int j(1); j<=n; ++j) ans[j] = scc[j] <= i;
			return true;
		}
	}
	return false;
}

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

	for (cin >> t; t; --t){
		cin >> k >> m; vct = n = k*3; Seg::build(1, 1, n);
		for (int lx, rx, ly, ry; m; --m){
			cin >> lx >> rx >> ly >> ry;
			Seg::conct(1, 1, n, lx, rx, ++vct, 1); Seg::conct(1, 1, n, ly, ry, vct, 0);
		}
		for (int i(1); i<=n; ++i) if (!dfn[i]) tarjan(i);
		// cout << sct << '\n';
		if (!calc()) cout << "NIE\n";
		else{
			cout << "TAK\n";
			for (int i(1); i<=n; ++i) cout << (ans[i] ? 'F' : 'R'); cout << '\n';
		}
		cnt = vct = sct = 0;
		for (int i(1); i<=vct; ++i){
			e[i].clear(); g[i].clear();
			dfn[i] = low[i] = val[i] = 0;
		}
	}

	return 0;
}