--description--

Working from left-to-right if no digit is exceeded by the digit to its left it is called an increasing number; for example, 134468.

Similarly if no digit is exceeded by the digit to its right it is called a decreasing number; for example, 66420.

We shall call a positive integer that is neither increasing nor decreasing a "bouncy" number; for example, 155349.

As n increases, the proportion of bouncy numbers below n increases such that there are only 12951 numbers below one-million that are not bouncy and only 277032 non-bouncy numbers below ${10}^{10}$.

How many numbers below a googol (${10}^{100}$) are not bouncy?

--hints--

nonBouncyNumbers() should return 51161058134250.

assert.strictEqual(nonBouncyNumbers(), 51161058134250);

--seed--

--seed-contents--

function nonBouncyNumbers() {

  return true;
}

nonBouncyNumbers();

--solutions--

// solution required