pascal - Задача про спираль

program spiral_count;

const
  cN = 50;
  cM = 50;

var
  i, j, N, M, tN, tM, count, iMiddle, jMiddle: integer;
  A: array[1..cN, 1..cM] of integer;

procedure spiral(i1, j1, i_N, jM: integer);
var
  _i, _j: integer;
begin
  _i := i1;
//  if j1 < jM then
    for _j := j1 to jM do 
    begin
      A[_i, _j] := count;
      inc(count);
    end;
//  if i1 < i_N then    
    for _i := i1+1 to i_N do 
    begin
      A[_i, _j] := count;
      inc(count);
    end;  
  if i1+1 < i_N then // вторая строка    
    for _j := jM-1 downto j1 do 
    begin
      A[_i, _j] := count;
      inc(count);
    end;
  if (j1+1) < jM then // второй столбец   
    for _i := i_N-1 downto i1 + 1 do 
    begin
      A[_i, _j] := count;
      inc(count);
    end;
end;

begin
  readln(N, M);
  tN := N;
  tM := M;
  iMiddle := N div 2;
  jMiddle := M div 2;
  
  count := 1;
  i := 1;
  j := 1;
  while i < tN do
    while j < tM do 
    begin
      spiral(i, j, tN, tM);
      inc(i);
      inc(j);
      dec(tN);
      dec(tM);
    end;
  
  for i := 1 to N do  begin
    for j := 1 to M do
      write( A[i,j]:3 );
    writeln;
  end;
  
end.