Помогите в оптимизации кода Опции

[Witaliy]

Всем привет!

У меня есть такой код:

program my;
var n,m,i,j : integer;
    k,q,res : longint;
    a,b: array[0..101,0..101] of byte;
begin
readln(n,m,k);
for i := 1 to n do
 begin
 for j := 1 to m do
  read(a[i,j]);
 readln;
end;
for q := 1 to k do
begin
for i := 1 to n do
  begin
  for j := 1 to m do
    begin
    if a[i,j] = 1 then
     begin
     b[i-1,j] := 1;
     b[i+1,j] := 1;
     b[i,j+1] := 1;
     b[i,j-1] := 1;
     end;
    end;
  end;
for i := 1 to n do
 for j := 1 to m do
  begin
  if a[i,j] = 1 then
   b[i,j] := 1;
  if b[i,j] = 1 then a[i,j] := 1;
 end;
end;
res := 0;
for i := 1 to n do
  for j := 1 to m do
    if a[i,j] = 1 then
     inc(res);
writeln(res);
end.

Но при прохождении тестов видаёт лимит времени.
1<N,M<=100
1<=K<=1000000

Спасибо!