program giaibaitap;
uses crt;
var i:integer;
a:string;
begin a:='Chao Mung Ban Den Dien Dan Tin Hoc';
for i:=1 to 78 do a:=' '+a; a:=a+a; clrscr;
repeat inc(i);
gotoxy(1,12);
write(copy(a,i,79));
delay(150);
if i=120 then begin i:=0; clrscr;
end;
until keypressed;
end.