import sys
#input = sys.stdin.readline
input = sys.stdin.buffer.readline #文字列はダメ
#sys.setrecursionlimit(1000000)
import bisect
#import itertools
#import random
#from heapq import heapify, heappop, heappush
#from collections import defaultdict 
#from collections import deque
#import copy
#import math
#from functools import lru_cache
#@lru_cache(maxsize=None)
#MOD = pow(10,9) + 7
#MOD = 998244353
#dx = [1,0,-1,0]
#dy = [0,1,0,-1]
#dx8 = [1,1,0,-1,-1,-1,0,1]
#dy8 = [0,1,1,1,0,-1,-1,-1]
#dx = [1,1,-1,-1]
#dy = [1,-1,1,-1]


def main():
    N,Q = map(int,input().split())
    A = list(map(int,input().split()))
    W = []
    for i,a in enumerate(A):
        wa = (1+a)*a//2
        W.append(wa)

    #print(W)
    SA = [0]
    for w in W:
        SA.append(SA[-1]+w)
    num = [0]
    for a in A:
        num.append(num[-1]+a)
    #print(SA)
    #print(num)
    #ret = []
    for _ in range(Q):
        s = int(input())
        if s > SA[-1]:
            print(-1)
            continue
        idx = bisect.bisect_right(SA,s)
        ans = num[idx-1]
        nokori = s - SA[idx-1]
        temp = calc(nokori)
        #print(ans,nokori)
        ans += temp
        print(ans)

def calc(v):
    if v == 0:
        return 0
    ng = 0
    ok = pow(10,5) + 100
    while abs(ok-ng) > 1:
        mid = (ok+ng)//2
        if (1+mid)*mid//2 >= v:
            ok = mid
        else:
            ng = mid
    return ok


if __name__ == '__main__':
    main()