function gameOfLifeIterator(b) {
  const a = (x, y) => b[x] && b[x][y]
  return b.map((r, x) =>
    r.map((_, y) => {
      let n = 0
      a(x - 1, y - 1) && n++
      a(x - 1, y) && n++
      a(x - 1, y + 1) && n++
      a(x, y - 1) && n++
      a(x, y + 1) && n++
      a(x + 1, y - 1) && n++
      a(x + 1, y) && n++
      a(x + 1, y + 1) && n++
      return (a(x, y) ? n > 1 && n < 4 : n === 3) ? 1 : 0
    }))
}