#include <stdio.h>

int main()
{
	int i, N, Q, A[101];
	scanf("%d %d", &N, &Q);
	for (i = 1; i <= N; i++) scanf("%d", &(A[i]));
	
	int j, k, x, l, r, m;
	long long sum[1000001];
	for (i = 1, k = 1, sum[0] = 0; i <= N; i++) for (j = 1; j <= A[i]; j++, k++) sum[k] = sum[k-1] + j;
	for (i = 1; i <= Q; i++) {
		scanf("%d", &x);
		l = 1;
		r = k;
		while (l < r) {
			m = (l + r) / 2;
			if (sum[m] >= x) r = m;
			else l = m + 1;
		}
		if (l < k) printf("%d\n", l);
		else printf("-1\n");
	}
	return 0;
}