#include<fstream>
#include<stack>
std::ifstream fin("nivele.in");
std::ofstream fout("nivele.out");
std::stack<int>st;
inline void solve()
{
    int n;
    fin>>n;
    for(int i=0; i<n; ++i)
    {
        int val;
        fin>>val;
        while(!st.empty() && st.top()==val)
        {
            st.pop();
            --val;
        }
        st.push(val);
    }
    if(st.size()==1 && st.top()==1)
        fout<<"DA\n";
    else
        fout<<"NU\n";
}
int main()
{
    int t;
    fin>>t;
    while(t--)
        solve();
    return 0;
}