# include <stack>
using namespace std ;

const char FIN[] = "nivele.in", FOU[] = "nivele.out" ;

int T, N ;

int main ( void ) {
    freopen ( FIN, "r", stdin ) ;
    freopen ( FOU, "w", stdout ) ;

    for ( scanf ( "%d", &T ) ; T ; --T ) {
        scanf ( "%d", &N ) ;

        stack < int > Q ;

        for ( int i = 1, A ; i <= N; ++i ) {
            scanf ( "%d", &A ) ;

            for ( ; ! Q.empty () && Q.top () == A && A ; Q.pop () , --A ) ;
            Q.push ( A ) ;
        }

        printf ( "%s\n", Q.size () == 1 && Q.top () == 1 ? "DA" : "NU" ) ;
    }

    return 0;
}