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())
    TA = list(map(int,input().split()))
    A = []
    for i in range(N):
        for j in range(i+1):
            A.append(TA[j])
    #print(A)
    SA = [0]
    for a in A:
        SA.append(SA[-1]+a)
    #print(SA)

    for _ in range(Q):
        s = int(input())
        if s > SA[-1]:
            print(-1)
            continue
        ans = bisect.bisect_right(SA,s) - 1
        print(ans)



if __name__ == '__main__':
    main()