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

Sum = [0] * (N+1)
l = [0] * (N + 1)
for i in range(N):
    Sum[i+1] = Sum[i] + A[i] * (A[i] + 1) // 2
    l[i+1] = l[i] + A[i]

def calc(x):
    if Sum[-1] < x:
        return -1
    end = N
    start = 0
    while end - start > 1:
        mid = end + start >> 1
        if Sum[mid] >= x:
            end = mid
        else:
            start = mid
    ans = l[start]
    x -= Sum[start]
    end = A[end-1]
    start = 0
    while end - start > 1:
        mid = end + start >> 1
        if mid * (mid + 1) // 2 >= x:
            end = mid
        else:
            start = mid
    return ans + end

for _ in range(Q):
    print(calc(int(input())))