hieutdo

async function fibo1(n) {
  if (n === 0 || n === 1) return n;
  const f1 = await fibo1(n - 1);
  const f2 = await fibo1(n - 2);
  return f1 + f2;
}

async function fibo2(n) {
  if (n === 0 || n === 1) return n;
  const [f1, f2] = await Promise.all([fibo2(n - 1), fibo2(n - 2)]);