program password;
uses crt;
var tk, mk: string;
begin
repeat
clrscr;
textcolor (white);
writeln ('Dang nhap de thoat khoi chuong trinh');
write ('nhap ten tai khoan: '); readln (tk);
write ('nhap mat khau: '); readln (mk);
if (tk='tencuaban_123') and (mk='123456789') then
exit;
if (tk<>'tencuaban_123') or (mk<>'123456789') then
textcolor (lightred);
writeln ('ten tai khoan hoac mat khau bi sai. vui long dang nhap lai');
readln;
until (tk='tencuaban_123') and (mk='123456789');
readln;
end.
