from bisect import bisect_left, bisect_right
from itertools import accumulate
import sys


def printe(*args, end="\n", **kwargs):
    print(*args, end=end, file=sys.stderr, **kwargs)


def main():
    N, Q = map(int, input().split())
    A = list(map(int, input().split()))
    A_accum = list(accumulate(A))
    B_partial = [a_elm * (a_elm + 1) // 2 for a_elm in A]
    B_partial_accum = list(accumulate(B_partial, initial=0))

    printe(B_partial_accum)
    printe(A_accum)

    for _ in range(Q):
        S = int(input())
        b_p_idx = bisect_right(B_partial_accum, S)
        if b_p_idx == len(B_partial_accum):
            print(-1)
            continue
        if B_partial_accum[b_p_idx - 1] == S:
            print(A_accum[b_p_idx - 2])
            continue
        min_a_idx = 0
        max_a_idx = A[b_p_idx - 1]
        while max_a_idx - min_a_idx > 1:
            mid_a_idx = (max_a_idx + min_a_idx) // 2
            if (1 + mid_a_idx) * (mid_a_idx) // 2 + \
                    B_partial_accum[b_p_idx - 1] >= S:
                max_a_idx = mid_a_idx
            else:
                min_a_idx = mid_a_idx
        print(A_accum[b_p_idx - 2] + max_a_idx)


if __name__ == "__main__":
    main()