#include <bits/stdc++.h>
using namespace std;
int n,T;
struct pnt
{
    int x,y;
    pnt(){}
    pnt(int a,int b)
    {
        x=a;
        y=b;
    }
};
vector < pnt > v;
int main()
{
    freopen("date.in","r",stdin);
    scanf("%d",&T);
    while (T--)
    {
        v.clear();
        scanf("%d",&n);
        int x,y;
        while (n--)
        {
            scanf("%d %d",&x,&y);
            v.push_back(pnt(x,y));
        }
        bool ok=true;
        for (int i=0;i<v.size() && ok;i++)
        {
            for (int j=i+1;j<v.size() && ok;j++)
            {
                if ((v[i].x>v[j].x && v[i].y<v[j].y) ||
                    (v[i].x<v[j].x && v[i].y>v[j].x))
                {
                    printf("Da\n");
                    ok=false;
                }
            }
        }
        if (ok) printf("Nu\n");
    }
    return 0;
}