#include "bits/stdc++.h"
using namespace std;
const int Len = 105;
int n,m,head[Len],cnt,in[Len],bg[Len],sm[Len];
bitset<105> bst[Len];
struct E
{
	int x,y;
	E(){x = y = 0;}
	E(int X,int Y){x = X , y = Y;}
}ee[Len * Len];
struct node
{
	int next,to;
}edge[Len * Len * 2];
inline void add(int from,int to)
{
	edge[++ cnt].to = to;
	edge[cnt].next = head[from];
	head[from] = cnt;
}
inline void clr(){cnt = 0;for(int i = 1 ; i <= n ; i ++) bst[i].reset() , bst[i].set(i , 1);memset(head , 0 , sizeof head);memset(in , 0 , sizeof in);}
inline void Top()
{
	queue<int> Q;
	for(int i = 1 ; i <= n ; i ++) if(!in[i]) bst[i].set(i , 1) , Q.push(i);
	while(!Q.empty())
	{
		int p = Q.front();Q.pop();
		for(int e = head[p] ; e ; e = edge[e].next)
		{
			int to = edge[e].to;
			in[to] --;
			bst[to] |= bst[p];
			if(!in[to]) Q.push(to);
		}	
	}
}
inline void work()
{
	clr();
	for(int i = 1 ; i <= m ; i ++) add(ee[i].x , ee[i].y) , in[ee[i].y] ++;
	Top();
}
int fa[Len];
inline bool cir()
{
	clr();	
	for(int i = 1 ; i <= m ; i ++) add(ee[i].x , ee[i].y) , in[ee[i].y] ++;
	queue<int> Q;int nms = 0;
	for(int i = 1 ; i <= n ; i ++) if(!in[i]) Q.push(i) , nms ++;
	while(!Q.empty())
	{
		int p = Q.front();Q.pop();
		for(int e = head[p] ; e ; e = edge[e].next)
		{
			int to = edge[e].to;
			in[to] --;
			if(!in[to]) Q.push(to) , nms ++;
		}	
	}
	return nms == n;
}
signed main()
{
	int T;scanf("%d",&T);
	while(T --)
	{
		scanf("%d %d",&n,&m);
		for(int i = 1 ; i <= m ; i ++)
		{
			int x,y;scanf("%d %d",&x,&y);
			ee[i] = E(x , y);
		}
		if(!cir()) 
		{
			for(int i = 1 ; i <= n ; i ++) putchar('0');
			puts("");
			continue;
		}
		work();
		for(int i = 1 ; i <= n ; i ++) bg[i] = bst[i].count() - 1;
		for(int i = 1 ; i <= m ; i ++) swap(ee[i].x , ee[i].y);
		work();
		for(int i = 1 ; i <= n ; i ++) sm[i] = bst[i].count() - 1;
		for(int i = 1 ; i <= n ; i ++)
		{
			int res = 1 , mn , mx;
			mn = sm[i] + 1 , mx = sm[i] + (n - bg[i] - sm[i]) + 1;
			res &= mn <= ((n + 1) / 2) && ((n + 1) / 2) <= mx;
			swap(sm[i] , bg[i]);
			mn = sm[i] + 1 , mx = sm[i] + (n - bg[i] - sm[i]) + 1;
			res &= mn <= ((n + 1) / 2) && ((n + 1) / 2) <= mx;
			if(res) putchar('1');
			else putchar('0');
		}
		puts("");
	}
	return 0;
}