#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define all(a) a.begin(),a.end()
#define vll vector<ll>
#define pll pair<ll,ll>
#define vpll vector<pll>
#define vi vector<int>
#define vvll vector<vll>
#define pb push_back 
#define ff first
#define ss second
const ll mod = 1e9+7,N = 1e6 +5;
// bool prime[N];
ll power(ll x, ll y){
  if(y == 0) return 1;
  ll p = power(x,y/2);
  p = (p*p)%mod;
  return (y&1)?(p*x)%mod : p;
}
void solve(){
    ll n,x,y,m;
    cin>>n>>m;
    vpll a;
    // vpll vec;
    for(ll i=0;i<m;i++){
      cin>>x>>y;
      // vec.pb({x,y});
      a.pb({y,x});
    }
    sort(all(a));
    bool ok=1;
    ll row=-1,last_col=-1;
    for(int i=0;i<m;i++){
      ll col = a[i].ff;
      if(row == -1){
        row = a[i].ss;
        if(a[i].ff == last_col) ok=0;
        last_col = a[i].ff;
      }else if(col == last_col) row=-1,last_col=-1;
      else{
        if((col - last_col)%2 == 0){
          if(a[i].ss != row){
            row=-1;
            last_col=col;
          }else ok=0;
        }else{
          if(a[i].ss == row){
            row=-1;
            last_col = col;
          }else ok=0;
        }
      }
    }
    if(row != -1) ok=0;
    cout<<(ok?"YES\n":"NO\n");
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    clock_t time_req;
    time_req = clock();
    ll test=1;
    cin>>test;
    for(ll i=1;i<=test;++i){
      solve();
    }
    time_req = clock()-time_req;
    //cout<<(float)(time_req)/CLOCKS_PER_SEC<<"\n";
    return 0;
}