#include <fstream>
#include <stack>

using namespace std;

int main() {
    ifstream in("nivele.in");
    ofstream out("nivele.out");
    int T; in >> T;
    for (; T > 0; --T) {
        int N; in >> N;
        stack<int> Stack;
        for (; N > 0; --N) {
            int Depth; in >> Depth;
            while (!Stack.empty() && Stack.top() == Depth) {
                Stack.pop();
                --Depth;
            }
            Stack.push(Depth);
        }
        if (static_cast<int>(Stack.size()) == 1 && Stack.top() == 1)
            out << "DA\n";
        else
            out << "NU\n";
    }
    in.close();
    out.close();
    return 0;
}