uses crt;
var tb,tc,nam: integer;
BEGIN
clrscr;
write('nhap tuoi bo va con: ');
readln(tb,tc);
nam := 0;
while tb <> tc * 3 do
begin
tb := tb + 1;
tc := tc + 1;
nam := nam + 1;
end;
write('sau ',nam,' nam nua thi tuoi bo gap 3 lan tuoi con.');
readln;
END.