#include <bits/stdc++.h>

int main() {
	int n, q, len = 0;
	scanf("%d%d", &n, &q);
	int a[100];
	for (int i = 0; i < n; i++) {
		scanf("%d", &a[i]);
		len += a[i];
	}
	long c_idx[101], c[101];
	c_idx[0] = 0;
	c[0] = 0;
	for (int i = 0; i < n; i++) {
		c_idx[i + 1] = c_idx[i] + a[i];
		c[i + 1] = c[i] + a[i] * (a[i] + 1) / 2;
	}
	for (int i = 0; i < q; i++) {
		int s;
		scanf("%d", &s);
		if (s > c[n]) {
			puts("-1");
			continue;
		}
		int l_idx = std::lower_bound(c, c + n + 1, s) - c;
		int l = c_idx[l_idx - 1], r = c_idx[l_idx];
		while (r - l > 1) {
			int mid = (l + r) / 2;
			int k = std::upper_bound(c_idx, c_idx + n + 1, mid) - c_idx;
			long d = mid - c_idx[k - 1];
			if (c[k - 1] + d * (d + 1) / 2 >= s) {
				r = mid;
			} else {
				l = mid;
			}
		}
		printf("%d\n", r);
	}
}