function flatten(nestedArrays: number[][]): number[] {
  const result: number[] = []

  const recursiveFlat = (arr: (number | number[])[]) => {
    arr.forEach((item) => {
      if (Array.isArray(item)) {
        recursiveFlat(item)
      } else {
        result.push(item)
      }
    })
  }

  recursiveFlat(nestedArrays)
  return result
}

export { flatten }