const n=30;
var
  i,y,d1,d2,uk:integer;a:array[0..n] of integer;
begin
  read(y);d1:=0;d2:=n;
  for i:=1 to n do
     read(a[i]);
  uk:=n div 2;
  while (a[uk]<>y) do
  begin
    if (a[uk]<y) and (a[uk+1]>y) then begin
                                        write('Not found');exit;
                                      end;
    if (a[uk]>y) and (a[uk-1]<y) then begin
                                        write('Not found');exit;
                                      end;
    if (a[uk]<y) then begin
                        d1:=uk;uk:=d2-((d2-d1) div 2);
                      end;
        if (a[uk]>y) then begin
                        d2:=uk;uk:=d1+((d2-d1) div 2);
                      end;
  end;
  write(uk);
end.