Const
 N=20;

Var
 A,B:Array[1..N] of Integer;
 i,j,S,P,Ifirst,Ilast:Integer;

Begin
 Randomize;
 Writeln('Initial array:');
 for i:=1 to N do
  begin
   A[i]:=-5+Random(10);
   if (i=5) or (i=17) then A[i]:=0;
   Write(A[i]:4);
  end;
 Writeln;
 Writeln;

 P:=1;
 for i:=1 to (N div 2) do P:=P*A[2*i];
 Writeln('Product = ',P);
 Writeln;
 Writeln;

 Ifirst:=0;
 Repeat
  Inc(Ifirst);
 Until A[Ifirst]=0;
 Ilast:=N+1;
 Repeat
  Dec(Ilast);
 Until A[Ilast]=0;
 S:=0;
 for i:=Ifirst+1 to Ilast-1 do S:=S+A[i];
 Writeln('Sum = ',S);
 Writeln;
 Writeln;

 j:=0;
 for i:=1 to N do
  if A[i]>=0 then
   begin
    Inc(j);
    B[j]:=A[i];
   end;
 j:=N+1;
 for i:=N downto 1 do
  if A[i]<0 then
   begin
    Dec(j);
    B[j]:=A[i];
   end;
 Writeln('New array:');
 for i:=1 to N do Write(B[i]:4);
 Readln
End.