#include <fstream>
#include <stack>
#include <string>

using namespace std;

ifstream in( "nivele.in" );
ofstream out( "nivele.out" );

const int NMAX = 50000;

int v[NMAX+2];
stack<int> st;
int N;
string ans[2] = {"NU\n", "DA\n"};

int main()
{
    int T;
    in >> T;
    while(  T--) {
        in >> N;
        for( int i = 1;  i <= N;  ++i ) {
            int x;
            in >> x;
            while( !st.empty() && st.top() == x ) {
                st.pop();
                --x;
            }
            st.push( x );
        }
        bool ok = 1;
        if( st.size() > 1 || st.top() != 1 ) ok = 0;
        out << ans[ok];
    }
    return 0;
}