Из массива z(20,20) в массив d(20) переписать наибольшие по модулю элементы каждого столбца z- Pascal(Паскаль)

Uses
  CRT;

Const
  nmmax = 20;

Type
  mas = array [1 .. nmmax, 1 .. nmmax] of integer;

var
  a: mas;
  b: array [1 .. nmmax] of integer;
  i, j, n, m, imax: integer;

procedure st(Var m: mas; k, l: integer);
Var
  ii, jj: integer;
begin
  for jj := 1 to l do
  begin
    imax := 1;
    for ii := 1 to k do
      if abs(m[ii, jj]) > abs(m[imax, jj]) then
        imax := ii;
    b[jj] := m[imax, jj];
  end;
end;

Begin
  repeat
    Write('Vvedite kol-vo strok: ');
    Readln(n);
  until n in [1 .. nmmax];
  repeat
    Write('Vvedite kol-vo stolbcov: ');
    Readln(m);
  until m in [1 .. nmmax];
  randomize;
  for i := 1 to n do
  begin
    for j := 1 to m do
    begin
      a[i, j] := random(10) - 4;
      write(a[i, j]:3);
    end;
    writeln;
  end;
  writeln;
  st(a, n, m);
  for i := 1 to m do
    write(b[i]:3);
  Readln

End.