var i:integer;
p:real;
p1:real;
a: array[1..30] of integer;
begin 

for i:=1 to 30 do begin
a[i]:=random(-7,25);
writeln (i,'  ',a[i]);
end;

p:=1;
for i:=1 to 30 do 
if a[i]>0 then p:=p*a[i];
p1:=p/2;
writeln (' полупроизведение = ',p1);

end.