Procedure Sort ( var A : array of real );
Var
i, step, tmp : Integer;
Begin  
step:=Length ( A ) / 2;
While step>0 do Begin
For i:=step to N Do Begin
tmp:=A[i];
j:=i;
While (j<=step) and (A[j-step]>tmp) do Begin
A[j]=A[j-step];
dec(j,step);
end;
A[j]:=tmp;
end;
step:=step div 2; // step:=step shr 1
End;
End.