#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];
ll dfs(ll now){
    ll cnt=1;
    if(vis[now]){
        return -1;
    }
    vis[now]=true;
    for(auto i:s[now]){
        cnt+=dfs(i);
    }
    return cnt;
}
ll dfs2(ll now){
    ll cnt=1;
    if(vis[now]){
        return -1;
    }
    vis[now]=true;
    for(auto i:x[now]){
        cnt+=dfs2(i);
        
    }
    return cnt;
}
ll ans[Q];
void solve(){
   ll n,m;cin>>n>>m;
   memset(ans,0,sizeof ans);
   bool ok=true;
   for (ll i = 1; i <= m; i++)
   {
    ll o,p;cin>>o>>p;
    if(o==p) ok=false;
    x[o].push_back(p);
    s[p].push_back(o);
   }
   if(ok==false){
    for (ll i = 1; i <= n; i++)
    {
        cout<<0;
    }cout<<"\n";
    return;
   }
    for (ll i = 1; i <= n; i++)
    {
        memset(vis,0,sizeof vis);
        ll l=dfs(i)-1;
        memset(vis,0,sizeof vis);
        ll r=dfs2(i)-1;
        if(l==-1 or r==-1 )cout<<0;
        else
        if((l+r==0 or l+r==1)or(l==n/2 and r==n/2)){
            cout<<1;
        }else cout<<0;
    }cout<<"\n";

    

}
int main(){
    ios;ll _=1;cin>>_;
    while (_--)solve();
    return 0;
}