В каждом столбце матрицы D[N,M] нулевые элементы переставить в начало столбца

Program massiv;
const N=10;
const M=10;
var D:array [1..N,1..M] of real;
f,b,i,j:integer;
c:real;
flag:boolean;
begin
write('vvedite razmernost massiva f-b');
readln(f,b);
for i:=1 to f do
for j:=1 to b do
readln(D[i,j]);
for j:=1 to b do
repeat flag:=true;
for i:=1 to f-1 do
if (D[i,j]<>0) and (D[i+1,j]=0) then
begin
c:=D[i,j];
D[i,j]:=D[i+1,j];
D[j+1,j]:=c;
flag:=false;
end;
until flag;
for i:=1 to f do begin
for j:=1 to b do
write (D[i,j]:3:2);
writeln;
end;
end.

Program matr;
 
const N = 10;
const M = 10;
 
var d: array [1..N, 1..M] of integer;
    i, j, k, t: integer;
 
begin
  randomize;
  writeln('Source array:');
  for i := 1 to n do
    begin
      for j := 1 to m do
        begin
          d[i,j] := random(5);
          write(d[i, j]:2)
        end;
      writeln
    end;
  for j := 1 to n do
    for i := 1 to n do
      if d[i, j] = 0
        then
          begin
            for k := i downto 2 do d[k, j] := d[k - 1, j];
            d[1, j] := 0
          end;
  writeln('Result array:');
  for i := 1 to n do
    begin
      for j := 1 to m do write(d[i,j]:2);
      writeln
    end;
  readln
end.