function equalStacks(h1, h2, h3) {
  let h1Total = h1.reduce((a, c) => a + c);
  let h2Total = h2.reduce((a, c) => a + c);
  let h3Total = h3.reduce((a, c) => a + c);

  function checkEquality(one, two, three) {
    if (one === two && two === three) {
      return true;
    }
    return false;
  }

  while (!checkEquality(h1Total, h2Total, h3Total)) {
    let numberToSubtract = 0;
    if (h1Total >= h2Total && h1Total >= h3Total) {
      numberToSubtract = h1.shift();
      h1Total -= numberToSubtract;
    } else if (h2Total >= h1Total && h2Total >= h3Total) {
      numberToSubtract = h2.shift();
      h2Total -= numberToSubtract;
    } else if (h3Total >= h1Total && h3Total >= h1Total) {
      numberToSubtract = h3.shift();
      h3Total -= numberToSubtract;
    }
  }

  return h1Total;
}