/*########################################################################
# File Name: F.cpp
# Author: SoMnus_L
# Mail: lr599909928@gmail.com
# Created Time:一  1/18 21:29:49 2021
########################################################################*/
#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define pb push_back
#define me memset
#define rep(a,b,c) for(int a=b;a<=c;++a)
#define per(a,b,c) for(int a=b;a>=c;--a)
const int N = 1e6 + 10;
const int mod = 1e9 + 7;
const int INF = 0x3f3f3f3f;
using namespace std;
typedef pair<int,int> PII;
typedef pair<ll,ll> PLL;
ll gcd(ll a,ll b) {return b?gcd(b,a%b):a;}
ll lcm(ll a,ll b) {return a/gcd(a,b)*b;}

int __;

bool cmp(PII a,PII b){
	if(a.se==b.se) return a.fi<b.fi;
	return a.se<b.se;
}

int main() {
    ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	cin>>__;
	while(__--){
		int n,m;
		cin>>n>>m;

		vector<PII> a(m);

		for(auto &[x,y]:a) cin>>x>>y;
	
		if(m&1) {cout<<"NO\n";continue;}	
		
		sort(a.begin(),a.end(),cmp);
		
		bool flag=true;

		rep(i,0,m-2){
			if(a[i].se==a[i+1].se && i&1){
				flag=false;
				break;
			}
		}

		for(int i=0;i<m-1;i+=2){
			if(a[i+1].fi==a[i].fi && (a[i+1].se-a[i].se)%2!=1) {flag=false;break;}
			if(a[i+1].fi!=a[i].fi && (a[i+1].se-a[i].se)%2!=0) {flag=false;break;}
		}

		if(flag) cout<<"YES\n";
		else cout<<"NO\n";

	}


    return 0;
}
