#include <fstream>
using namespace std;
const int NMAX = 50005;
int st[NMAX];

int main() {
    int T, n, x;
    ifstream cin("nivele.in");
    ofstream cout("nivele.out");
    cin >> T;
    while(T > 0) {
        cin >> n;
        int top = 0;
        for(int i = 1; i <= n; i++) {
            cin >> x;
            st[++top] = x;
            while(top > 1 && st[top] == st[top - 1]) {
                st[--top]--;
            }
        }
        if(top == 1 && st[top] == 1) {
            cout << "DA\n";
        }
        else {
            cout << "NU\n";
        }
        T--;
    }
    return 0;
}