--description--

How many integers $0 ≤ n < {10}^{18}$ have the property that the sum of the digits of $n$ equals the sum of digits of $137n$?

--hints--

digitalSignature() should return 20444710234716470.

assert.strictEqual(digitalSignature(), 20444710234716470);

--seed--

--seed-contents--

function digitalSignature() {

  return true;
}

digitalSignature();

--solutions--

// solution required