#include<bits/stdc++.h>
#include<unordered_map>

using namespace std;

#define int long long
#define endl '\n'
#define ULL unsigned long long
#define xx first
#define yy second
#define PII pair

const int MAXN = 1e2 + 10;
const int MOD = 998244353;
const int mod = 1e9 + 7;
const double eps = 1e-8;
int _x[] = { 1,-1,0,0 };
int _y[] = { 0,0,1,-1 };
int arr[MAXN];

int gr[MAXN][MAXN];
int to[MAXN][2];


bool floyd(int n)
{
	for(int k=1;k<=n;k++)
		for(int i=1;i<=n;i++)
			for (int z = 1; z <= n; z++)
				if (gr[i][k] && gr[k][z])
					gr[i][z] = 1;
	for(int i=1;i<=n;i++)
		for (int z = 1; z <= n; z++)
		{
			if (gr[i][z] && gr[z][i])
				return false;
			if (gr[i][z])
			{
				to[i][0]++;
				to[z][1]++;
			}
		}
	return 1;
}

void init()
{
	memset(gr, 0, sizeof(gr));
	memset(to, 0, sizeof(to));
}

signed main(void)
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int t;
	cin >> t;
	while (t--)
	{
		int n, m;
		cin >> n >> m;
		init();
		for (int i = 1; i <= m; i++)
		{
			int a, b;
			cin >> a >> b;
			gr[a][b] = 1;
		}
		if (!floyd(n))
		{
			for (int i = 1; i <= n; i++)
				cout << 0;
			cout << endl;
			continue;
		}
		for (int i = 1; i <= n; i++)
		{
			if (to[i][0] < ((n+1) >> 1) && to[i][1] < ((n+1) >> 1))
				cout << 1;
			else
				cout << 0;
		}
		cout << endl;

	}


	return 0;
}