CONTOH program pascal perulangan for to do

A. PROGRAM FOR TO DO
program for_to_do;
uses wincrt;
label back;
var
 i:byte;
 k,awal,akhir:integer;
 rata,jum:real;
begin
back:
clrscr;
write('Nilai Awal  = ');readln(awal);
write('Nilai Akhir = ');readln(akhir);
if awal<=akhir then
begin
for i:=awal to akhir do
if i mod 2=1 then
begin
jum:=jum+i;
awal:=awal+2;
k:=k+1;
end;
end
else goto back;
rata:=jum/k;
writeln('rata-rata = ',rata:2:2);
     write('================================================================================');
     writeln('                      ==*RICKYSEPRIYANTO_13010241*==');
     writeln('                      ==================================');
end.

B. PROGRAM KELIPATAN MENGUNAKAN FOR TO DO
program kelipatan_3;
uses wincrt;
var i:integer;
begin
writeln('kelipatan 3 sampai 21:');
for i:=3 to 21 do
if i mod 3 =0 then
writeln(i);
end.