#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define endl '\n'
const ll maxn = 100 + 5;
ll T;
ll n, m;
vector<ll>to[maxn];
vector<ll>to2[maxn];
ll sz[maxn];
ll sz2[maxn];
bool vis[maxn];
void dfs(ll u, ll s) {
	if (vis[u]) return;
	vis[u] = true;
	sz[s]++;
	sz2[u]++;
	for (auto v : to[u]) {
		dfs(v, s);
	}
}
ll in[maxn];
bool topu() {
	queue<ll>q;
	for (ll i = 1; i <= n; i++)if (!in[i])
		q.push(i);
	while (!q.empty()) {
		ll u = q.front();
		q.pop();
		for (auto v : to[u]){
			in[v]--;
			if (!in[v])
				q.push(v);
		}
	}
	for (ll i = 1; i <= n; i++)if (in[i])
		return false;
	return true;
}
int main()//H
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin >> T;
	while (T--) {
		for (ll i = 1; i <= n; i++)sz[i] = sz2[i] = in[i] =0,to[i].clear(), to2[i].clear();
		cin >> n >> m;
		bool flag = true;
		for (ll i = 1; i <= m; i++) {
			ll a, b; cin >> a >> b;
			if (a == b)flag = false;
			to[a].push_back(b);
			in[b]++;
		}
		vector<bool>ans(n + 1);
		if (topu()&&flag) {
			for (ll i = 1; i <= n; i++) {
				memset(vis, false, sizeof(vis));
				dfs(i, i);
			}
		}
		for (ll i = 1; i <= n; i++) {
			if (sz[i] - 1 <= n / 2 && sz2[i] - 1 <= n / 2 && flag)ans[i] = true;
			else ans[i] = false;
			cout << ans[i];
		}
		cout << endl;
	}
}