#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

char*mmap();
#define rd(v) int v=0;{int _c;while(_c=*rp++-48,_c>=0)v=v*10+_c;}
char wbuf[1<<25];

int d[100001];

main(){
	char*rp=mmap(0l,1l<<25,1,2,0,0ll);
	char*wp=wbuf;

	rd(t);
	for(;t--;){
		rd(n);
		memset(d+1,0,n*sizeof*d);
		rd(m);
		m<<=1;
		while(m--){
			rd(u);
			++d[u];
		}
		long e=0;
		for(int i=1;i<=n;++i){
			int di=d[i];
			if(di<64){
				if(e&1<<di){
					*(int*)wp='\nseY';
					wp+=4;
					goto done;
				}
				e|=1<<di;
			}
		}
		*(int*)wp='\noN';
		wp+=3;
		done: ;
	}
	write(1,wbuf,wp-wbuf);
	_exit(0);
}