from bisect import bisect_left
from itertools import accumulate


def main():
    N, Q = map(int, input().split())
    A = list(map(int, input().split()))

    B = []
    for idx in range(N):
        B.extend(A[:idx + 1])
    B_accum = list(accumulate(B, initial=0))
    for _ in range(Q):
        S = int(input())
        idx = bisect_left(B_accum, S)
        if idx == len(B_accum):
            print(-1)
        else:
            print(idx)


if __name__ == "__main__":
    main()