from itertools import accumulate
from bisect import bisect_left


def main():
    n, q = map(int, input().split())
    a = [0] + list(map(int, input().split()))
    aa = [ai * (ai + 1) // 2 for ai in a]
    acc = list(accumulate(aa))
    for _ in range(q):
        s = int(input())
        if s > acc[-1]:
            print(-1)
            continue

        k = bisect_left(acc, s)
        if s == acc[k]:
            print(sum(a[:k + 1]))
            continue

        left = 0
        right = a[k] + 1
        while right - left > 1:
            mid = (right + left) // 2
            if acc[k - 1] + mid * (mid + 1) // 2 >= s:
                right = mid
            else:
                left = mid
        print(sum(a[:k]) + right)


if __name__ == "__main__":
    main()