#include <bits/stdc++.h>
/* 
 Always code as if the guy who ends up maintaining your code will be a violent psychopath who knows where you live.
 — Rick Osborne
  */
using namespace std;
typedef pair <int,int> PII;
typedef vector <int> VI; 
typedef vector < PII > VPII;
int main()
{
    int tc;
    scanf("%d",&tc);
		while (tc--)
    {
        int m, n;
        scanf("%d %d",&m, &n);
				VPII segm;
        for(int i=0;i<n;i++)
        {
            int st, en;
            scanf("%d %d",&st, &en);
            if(st<=en)
            {
                segm.push_back(make_pair(st,en));
                segm.push_back(make_pair(st+m,en+m));
            }
            else
                segm.push_back(make_pair(st,en+m));
        }
				if(n>m)
        {
            puts("NO");
            continue;
        }
        sort(segm.begin(),segm.end());
        
				int T=0;
        int i=0;
        set < PII > que;
        bool ok = true;
        while(true)
        {
            if(que.empty())
            {
                if(i==segm.size())
                    break;
                else
                    T = segm[i].first;
            }
        
						while(i<segm.size() && segm[i].first==T)
            {
                que.insert(make_pair(segm[i].second,i));
                i++;
            }
            
						int ind = que.begin()->second;
            que.erase(que.begin());
            
						if(!(T>=segm[ind].first && T<=segm[ind].second))
            {
                ok = false;
                break;
            }
            T++;
        }
        puts(ok?"YES":"NO");
    }
}