function iteration(acc, head, rest) {
  if (head) {
    acc.add(head)
  }

  if (rest.length === 0) {
    return
  }

  const [next, ...nextRest] = rest
  
  for (const item of next) {
    iteration(acc, `${head} ${item}`, nextRest)
  }
}

function calculateAllCombinations(arrays) {
  const acc = new Set()
  iteration(acc, '', arrays)
  return Array.from(acc)
}

calculateAllCombinations([
  ['One', 'Two', 'Three'],
  ['1', '2', '3'],
  ['-', '+', '=']
])