--description--

What is the length of the shortest pipe, of internal radius 50mm, that can fully contain 21 balls of radii 30mm, 31mm, ..., 50mm?

Give your answer in micrometres (${10}^{-6}$ m) rounded to the nearest integer.

--hints--

spherePacking() should return 1590933.

assert.strictEqual(spherePacking(), 1590933);

--seed--

--seed-contents--

function spherePacking() {

  return true;
}

spherePacking();

--solutions--

// solution required