from bisect import bisect_left

n, q = map(int, input().split())
A = list(map(int, input().split()))
AA = [0]
I = [0]
for i in range(n):
    s = A[i] * (A[i] + 1) // 2
    AA.append(AA[-1] + s)
    I.append(I[-1] + A[i])

for _ in range(q):
    s = int(input())
    idx = bisect_left(AA, s)
    idx -= 1
    if idx == n:
        print(-1)
        continue
    s -= AA[idx]
    left = 0
    right = A[idx]
    while right - left > 1:
        mid = (left + right) // 2
        if mid * (mid + 1) // 2 >= s:
            right = mid
        else:
            left = mid
    print(I[idx] + right)