Помогите, пожалуйста, написать комментарии к программе

uses crt;
type stack=^data;
data=record
fio:string[10];
num:longint;
link:stack;
end;
var roof,temp:stack;
f:text;
ch:char;
i:integer;

procedure out;
var temp:stack;
j:integer;
begin
j:=0;
temp:=roof;
while temp^.link<>nil do
begin
j:=j+1;
writeln(j:3,'. ',temp^.num:5,' ',temp^.fio);
temp:=temp^.link;
end;
end;

procedure del;
var temp:stack;
num:integer;
cnt:integer;
begin
writeln('Enter num of deleted element');
readln(num);
if num=1
then
roof:=roof^.link
else
begin
temp:=roof;
for cnt:=1 to num-2 do
if temp^.link^.link=nil
then
break
else
temp:=temp^.link;
if temp^.link^.link<>nil
then
begin
temp^.link:=temp^.link^.link;
writeln('deleted');
end;
end;
end;

procedure add;
var temp:stack;
begin
new(temp);
temp^.link:=roof;
roof:=temp;
writeln('Enter number and name');
readln(temp^.num,ch,temp^.fio);
writeln('Added');
end;

begin
clrscr;
i:=-1;
assign(f,'data.db');
reset(f);
new(temp);
roof:=temp;
temp^.link:=nil;
while (not eof(f)) do
begin
readln(f,temp^.num,ch,temp^.fio);
new(temp^.link);
temp:=temp^.link;
temp^.link:=nil;
end;
writeln('Instruction:');
writeln('0 - exit');
writeln('1 - print stack');
writeln('2 - delete record');
writeln('3 - add record');
while (i<>0) do
begin
write('>');
readln(i);
case i of
1:out;
2:del;
3:add;
end;
end;
temp:=roof;
rewrite(f);
while temp^.link<>nil do
begin
writeln(f,temp^.num,' ',temp^.fio,' ');
temp:=temp^.link;
end;
close(f);
end.