#include <fstream>
using namespace std;
ifstream in("bitona.in");
ofstream out("bitona.out");
int main()
{
    int n,flag=0,i,x,y,p=-1,p2=-1,k=0,k2=0,z,m;
    in>>n;
    in>>x;
    z=x;
    for(i=1;i<=n-1;i++)
    {    in>>y;
    if(i==1) if(x>y) m=1;
                    else  if(x<y) m=0;
        if(x>y) {
                p=1;
        }
        if(x<y) {
            p2=1;
        }
        if(p==1&&p2==1&&flag==0&&x<y) {flag++;
                                    p=0;
                                    p2=0;
                                    k=0;
                                    }
        else
            if(p==1&&p2==1&&flag==0&&x>y) { flag++;
                                    p=0;
                                    p2=0;
                                    k=1;
                                    }
        else
        if(p==1&&p2==1) {flag++;
                                    p=0;
                                    p2=0;
                                    k=0;
                                    }
     if(i==n-1&&x>y)  k2=1;
     else if(i==n-1&&x<y) k2=0;






                x=y;
        }
        if(n==1||n==2) out<<"NU";
        else
        if(p==-1&&p2==-1) out<<"NU";
        else
        if(flag>2) out<<"NU";
        else out<<"DA";
return 0;

}