uses Crt;
Var
   A:array[1..30,1..30] of real;
   N,k,O,i,j:integer;
   P:real;
Begin
ClrScr;
Randomize;
Write('N = ');
ReadLn(N);
O:=N div 2+N mod 2+1;
WriteLn('Ââåäèòå ìàòðèöó âåùåñòâåííûõ ÷èñåë A(',N,',',N,'):');
For i:= 1 to N do
    Begin
    For j:= 1 to N do
        Begin
        A[i,j]:=random*21-10;
        if (O<=i)and(i<N)and(j<i)and(j>=O) then
           if A[i,j]<0 then TextBackground(12)
           else TextBackground(14)
        else TextBackground(2);
        Write(A[i,j]:5:2,' ');
        End;
    WriteLn
    End;
WriteLn;
k:=0;
P:=1;
For i:= O to N-1 do
    For j:= O to N do
        if j < i then
           if A[i,j] < 0 then
              Begin
              k:=k+1;
              P:=P*A[i,j]
              End;
TextBackground(0);
if k=0 then WriteLn('Èñêîìûõ ýëåìåíòîâ íåò')
else WriteLn('P = ',P);
ReadLn
End.