#include<fstream.h>
fstream f("sir.in", ios::in);
 void main()
  { int x,n,m;
    f>>n;
    do{ f>>x;
      } while(x%2==1);
    m=x;
    int p=1;
    while(!f.eof())
      { do{f>>x;
	  }while(x%2==1);
       if(x>=m) m=x;
	 else p=0;
      }
   if(p==1) cout<<"da";
     else cout<<"nu";
   }