#include <bits/stdc++.h>
using namespace std;
long long t,n,l,r;
double damage,totalDamage,h;
int main(){
  freopen("battle.in","r",stdin);
  freopen("battle.out","w",stdout);
  scanf("%lld",&t);
  while(t--){
    scanf("%lld%lf",&n,&h);
    totalDamage=0.0;
    for(int i=0; i<n; i++){
      scanf("%lld%lld",&l,&r);
      damage=(l+r)/2.0+0.5;
      totalDamage+=damage;
    }
    //cout << totalDamage << endl;
    if(totalDamage>=h)cout << "YES\n";
    else cout << "NO\n";
  }
  return 0;
}