#include <bits/stdc++.h>

using namespace std;

const int N = 2e6 + 10;

vector<int> g[N], G[N], R[N];
int tot, val[N], sz[N], dfn[N], low[N], vis[N], stk[N], id[N], tim, top, cnt, n, m;

inline void add(int u, int v) { g[u].emplace_back(v); }

struct SGT {
  int t[N];
  
  void build(int p, int l, int r, int f) {
    if (l == r) {
      t[p] = l;
      vector<int>().swap(g[l]);
      return;
    }
    t[p] = ++tot;
    vector<int>().swap(g[tot]);
    int m = (l + r) / 2;
    build(p * 2, l, m, f);
    build(p * 2 + 1, m + 1, r, f);
    if (f) ::add(t[p * 2], t[p]), ::add(t[p * 2 + 1], t[p]);
    else ::add(t[p], t[p * 2]), ::add(t[p], t[p * 2 + 1]);
  }

  void add(int p, int l, int r, int ql, int qr, int id, int f) {
    if (ql <= l && r <= qr) {
      if (f) ::add(t[p], id);
      else ::add(id, t[p]);
      return;
    }
    int m = (l + r) / 2;
    if (ql <= m) add(p * 2, l, m, ql, qr, id, f);
    if (qr > m) add(p * 2 + 1, m + 1, r, ql, qr, id, f);
  }
} sgt[2];

void tarjan(int u) {
  dfn[u] = low[u] = ++tim;
  vis[u] = 1, stk[++top] = u;
  for (int v : g[u]) {
    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]) {
    cnt++;
    sz[cnt] = 0;
    int v;
    do {
      v = stk[top--];
      vis[v] = 0;
      id[v] = cnt;
      sz[cnt] += val[v];
    } while (u != v);
  }
}

void print(int x) {
  cout << "TAK\n";
  for (int i = 1; i <= 3 * n; i++) {
    cout << (vis[id[i]] == x ? 'F' : 'R');
  }
  cout << '\n';
}

bool check(int u) {
  fill(vis + 1, vis + cnt + 1, 0);
  queue<int> q;
  q.emplace(u);
  int sum = sz[u];
  vis[u] = 1;
  while (q.size()) {
    int u = q.front();
    q.pop();
    for (int v : G[u]) if (!vis[v]) {
      sum += sz[v];
      vis[v] = 1;
      q.emplace(v);
    }
  }
  if (sum <= 2 * n) {
    print(1);
    return 1;
  }
  fill(vis + 1, vis + cnt + 1, 0);
  q.emplace(u);
  sum = sz[u];
  while (q.size()) {
    int u = q.front();
    q.pop();
    for (int v : R[u]) if (!vis[v]) {
      sum += sz[v];
      vis[v] = 1;
      q.emplace(v);
    }
  }
  if (sum <= 2 * n) {
    print(0);
    return 1;
  }
  return 0;
}

void solve() {
  cin >> n >> m;
  tot = 3 * n;
  sgt[0].build(1, 1, 3 * n, 0);
  sgt[1].build(1, 1, 3 * n, 1);
  while (m--) {
    int a, b, c, d;
    cin >> a >> b >> c >> d;
    int id = ++tot;
    sgt[1].add(1, 1, 3 * n, a, b, id, 1);
    sgt[0].add(1, 1, 3 * n, c, d, id, 0);
  }
  fill(val + 1, val + tot + 1, 0);
  fill(dfn + 1, dfn + tot + 1, 0);
  fill(val + 1, val + 3 * n + 1, 1);
  fill(vis + 1, vis + tot + 1, 0);
  tim = top = cnt = 0;
  for (int i = 1; i <= tot; i++) {
    if (!dfn[i]) tarjan(i);
  }
  int sum = 0;
  for (int i = 1; i <= cnt; i++) {
    sum += sz[i];
    vis[i] = 1;
    if (sum >= n && sum <= 2 * n) {
      print(1);
      return;
    }
  }
  for (int i = 1; i <= cnt; i++) {
    vector<int>().swap(G[i]);
    vector<int>().swap(R[i]);
  }
  for (int i = 1; i <= tot; i++) {
    for (int j : g[i]) {
      if (id[i] != id[j]) {
        G[id[i]].emplace_back(id[j]);
        R[id[j]].emplace_back(id[i]);
      }
    }
  }
  for (int i = 1; i <= cnt; i++) {
    if (sz[i] > n && check(i)) return;
  }
  cout << "NIE\n";
}

int main() {
  freopen("1.in", "r", stdin);
  cin.tie(0)->sync_with_stdio(0);
  int T;
  cin >> T;
  while (T--) solve();
  return 0;
}