//Shirosaki Hana kawaii
#include<bits/stdc++.h>
const int QaQ=4e6+5;
const int QWQ=8e5+5;
using namespace std;
using ll=long long;
inline int read(){
    int x=0,f=1; char ch=getchar();
    for (;ch<'0'||ch>'9';ch=getchar())
        if (ch=='-') f=-1;
    for (;ch>='0'&&ch<='9';ch=getchar())
        x=(x<<1)+(x<<3)+(ch^48);
    return x*f;
}
int dfn[QWQ],low[QWQ],scc[QWQ],w[QWQ],Cnd,now;
int T,n,m,cnt,head[QWQ],Tnd,Dnd,tot,rev[QWQ];
bool ins[QWQ],is[QWQ],chs[QWQ]; int du[QWQ];
stack<int> stk; queue<int> q; bool vis[QWQ];
struct node{ int to,next; } E[QaQ];
vector<int> e[QWQ],g[QWQ];
inline void append(int x,int y){
	E[++cnt]={y,head[x]},head[x]=cnt;
}
inline void add(int u,int v){
	append(u,v),append(v+Dnd,u+Dnd);
}
#define mid (l+r>>1)
void make(int k,int l,int r){
	if (l==r){
		rev[l]=k,is[k]=1; 
		append(k,k+Dnd);
		append(k+Dnd,k);
		Tnd=max(Tnd,k+Dnd);
		return ;
	}
	make(k<<1,l,mid),make(k<<1|1,mid+1,r);
	add(k,k<<1),add(k,k<<1|1);
}
void change(int k,int l,int r,int ll,int rr,bool tp){
	if (ll<=l&&rr>=r){
		if (!tp) append(Tnd,k);
		else append(k+Dnd,Tnd);
		return ;
	}
	if (ll<=mid) change(k<<1,l,mid,ll,rr,tp);
	if (mid<rr) change(k<<1|1,mid+1,r,ll,rr,tp);
}
inline void Edd(int l1,int r1,int l2,int r2){
	change(1,1,3*n,l1,r1,1);
	change(1,1,3*n,l2,r2,0);
}
void tarjan(int u){
	low[u]=dfn[u]=++tot;
	stk.push(u),ins[u]=1;
	for (int i=head[u],v;i;i=E[i].next)
		if (!dfn[v=E[i].to])
			tarjan(v),low[u]=min(low[u],low[v]);
		else if (ins[v]) low[u]=min(low[u],dfn[v]);
	if (low[u]==dfn[u]){
		scc[u]=++Cnd,w[Cnd]+=is[u];
		while (stk.top()!=u){
			w[Cnd]+=is[stk.top()];
			scc[stk.top()]=Cnd;
			ins[stk.top()]=0;
			stk.pop();
		} 
		ins[u]=0,stk.pop();
	}
}
inline void out(){
	puts("TAK");
	for (int i=1;i<=3*n;i++)
		putchar(chs[scc[rev[i]]] ? 'F':'R');
	puts("");
}
inline bool ckbig(int s){
	for (int i=1;i<=Cnd;i++) chs[i]=0;
	q.push(s),now=w[s],chs[s]=1;
	while (!q.empty()){
		int u=q.front(); q.pop();
		for (int v:e[u]) if (!chs[v])
			chs[v]=1,now+=w[v],q.push(v);
	}
	if (n<=now&&now<=2*n) out();
	return n<=now&&now<=2*n;
}
inline void clean(){
	while(q.size())q.pop();
	for (int i=1;i<=Tnd;i++)
		dfn[i]=scc[i]=ins[i]=head[i]=rev[i]=is[i]=0;
	for (int i=1;i<=Cnd;i++)
		g[i].clear(),e[i].clear(),w[i]=chs[i]=du[i]=0;
	Tnd=cnt=tot=Cnd=0,Dnd=12*n;
}
signed main(){
	for (T=read();T--;){
		n=read(),m=read(),clean();
		make(1,1,3*n);
		for (int i=1;i<=m;i++){
			int l1=read(),r1=read();
			int l2=read(),r2=read();
			++Tnd,Edd(l1,r1,l2,r2);
		}
		for (int i=1;i<=Tnd;i++)
			if (!dfn[i]) tarjan(i);
		for (int u=1;u<=Tnd;u++)
		for (int i=head[u],v;i;i=E[i].next)
			if (scc[u]!=scc[v=E[i].to])
				e[scc[u]].push_back(scc[v]),
				g[scc[v]].push_back(scc[u]),du[scc[u]]++;
		bool ok=0; vector<int> st;
		for (int i=1;i<=Cnd;i++){
			if (w[i]>2*n){ puts("NIE"),ok=1; break; }
			if (w[i]>=n) st.push_back(i);
		}
		if (ok) continue;
		if (!st.size()){
			for (int i=1;i<=Cnd;i++)
				if (!du[i]) q.push(i); now=0;
			while (!q.empty()){
				int u=q.front(); q.pop();
				now+=w[u],chs[u]=1;
				if (now>=n) break;
				for (int v:g[u])
					if (!--du[v]) q.push(v);
			} out(); continue;
		}
		while (st.size()){
			ok=ckbig(st.back()); if (ok) break;
			for (int i=1;i<=Cnd;i++) vis[i]=chs[i]=0;
			q.push(st.back()),vis[st.back()]=1;
			while (!q.empty()){
				int u=q.front(); q.pop();
				for (int v:g[u]) q.push(v),vis[v]=1;
			} now=0;
			for (int i=1;i<=Cnd;i++)
				if (!vis[i]) now+=w[i],chs[i]=1;
			if (now>=n){ out(),ok=1; break; }
			st.pop_back();
		}
		if (!ok) puts("NIE");
	}
    return 0;
}