export function maxWindowSum(numbers: number[], k: number): number {
  let rt:number[] = []
  for(let i=0;i<numbers.length;i++){
    rt.push(
      i == 0 ? numbers[i] : numbers[i]+rt[rt.length-1]
    )
  }
  let rest:number[] = []
  for(let i=0;i<numbers.length-k+1;i++){
    if(i==0){
      rest.push(rt[i+k-1])
    }else{
      rest.push(
        rt[i+k-1]-rt[i-1]
      )
    }
  }

  return rest.length > 0 ? Math.max(...rest) : -1
}