#include<bits/stdc++.h>
#define ios ios::sync_with_stdio(0),cin.tie(0),cout.tie(0)
using namespace std;using ll = long long;using PLL = pair<ll,ll>;
const ll MAX = 1e18;const ll MIN = -1e18;const ll INF=0x3f3f3f3f;
const ll Q = 2000+9;const ll MOD = 1e9 + 7;
vector<ll> s[Q];
vector<ll> x[Q];
bool vis[Q];
int inde;

ll dfs(ll now){
    ll cnt=1;
    if(vis[now]==false)
    cnt=1;
    else cnt=0;
    vis[now]=true;
    if(inde == -1) return 0;
    for(auto i:s[now]){
        if(i == inde) {inde = -1;return 0;}
        cnt+=dfs(i);
    }
    return cnt;
}
ll dfs2(ll now){
     ll cnt;
    if(vis[now]==false)
    cnt=1;
    else cnt=0;
    vis[now]=true;
    if(inde == -1) return 0;
    for(auto i:x[now]){
        if(i == inde) {inde = -1;return 0;}
        cnt+=dfs2(i);
    }
    return cnt;
}
ll ans[Q];
void solve(){
   ll n,m;cin>>n>>m;
   memset(ans,0,sizeof ans);
   for (ll i = 1; i <= n; i++)
   {
        s[i].clear();
        x[i].clear();
   }
   
   for (ll i = 1; i <= m; i++)
   {
    ll o,p;cin>>o>>p;
    x[o].push_back(p);
    s[p].push_back(o);
   }
    for (ll i = 1; i <= n; i++)
    {   
        inde = i;
        memset(vis,0,sizeof vis);
        ll l=dfs(i)-1;
        if(inde == -1) {
            for (ll i = 0; i < n; i++)
            {
                cout<<0;
            }cout<<"\n";
            return;
            
        }
        inde = i; 
        memset(vis,0,sizeof vis);
        ll r=dfs2(i)-1;
        if(inde == -1) {
            for (ll i = 0; i < n; i++)
            {
                cout<<0;
            }cout<<"\n";
            return;
        }

    //cout<<l<<" "<<r<<"\n";
        if(l<=(n)/2 and r<=(n)/2) ans[i]=1;
        else ans[i]=0;
    }

    for (ll i = 1; i <= n; i++)
    {
        cout<<ans[i];
    }cout<<"\n";
    
}
int main(){
    ios;ll _=1;cin>>_;
    while (_--)solve();
    return 0;
}