if eniboby knous what is error? please help me, make a kindness.



const b:array [1..7] of string=
('mon','tue','wed','thu','fri','sat','sun');
      v:array [1..12] of shortint=
(31,28,31,30,31,30,31,31,30,31,30,31);

var data,month,year,q,l,t,r,m,n,i,j,k,x:integer;
    pir,pir1:string;
    d:array [1..7,1..7] of string;

procedure readdata;
  begin
    readln (data,month,year);
  end;

function leap(i:word):boolean;
  begin
    leap:=((i mod 4=0)and(i mod 100<>0))or(i mod 400=0);
  end;

procedure first_jan_of_year;
  begin
    j:=0;
    for i:=1 to year do
      begin
        if leap(i) then
          j:=(j+2) mod 7
        else
          j:=(j+1) mod 7;
      end;
  end;

procedure find_first_day;
  begin
    for i:=1 to month-1 do
      if (leap(year)) and (i=2) then
        k:=k+29
      else
        k:=k+v[i];
    if k<>0 then
      begin
        k:=k mod 7;
        if k=0 then
          k:=7;
      end;
    j:=(j+k) mod 7;
    if j=0 then
      j:=7;
    if year=1600 then
      j:=6;
  end;

procedure how_many_day_are_in_the_month;
  begin
    if (leap(year)) and (month=2) then
      x:=29
    else
      x:=v[month];
  end;

procedure weeks_days;
  begin
    d[1,1]:='mon';d[2,1]:='tue';d[3,1]:='wed';
    d[4,1]:='thu';d[5,1]:='fri';d[6,1]:='sat';d[7,1]:='sun';
  end;

procedure make_calendar;
  begin
    r:=0;
    for l:=2 to 7 do
      for i:=j to 7 do
        begin
          inc (r);
          if r>x then
            exit;
           str (r,d[i,l]);
           if r=data then
             if (length(d[i,l])=2) then
               d[i,l]:=' [' +d[i,l]+']'
             else
               d[i,l]:='  [' +d[i,l]+']'
           else
             begin
               if d[i,l-1]='' then
                 d[i,l]:='     ' +d[i,l]+' '
               else
                 begin
                   if length(d[i,l])=2 then
                     d[i,l]:='  ' +d[i,l]+' '
                   else
                     d[i,l]:='   ' +d[i,l]+' ';
                 end;
             end;
           if i=7 then
             j:=t+1;

        end;
  end;

procedure change;
  begin
    for i:=1 to 7 do
      for j:=1 to 7 do
        if d[i,j]='' then
          d[i,j]:='   ';
  end;

procedure print;
  begin
    for i:=1 to 7 do
      for j:=1 to 8 do
        if j>7 then
          writeln
        else
          write (d[i,j]);
  end;
begin
  readdata;
  first_jan_of_year;
  find_first_day;
  how_many_day_are_in_the_month;
  weeks_days;
  make_calendar;
  change;
  print;
end.