#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;
	}

	auto total = [&](int idx) {
		int k = std::upper_bound(c_idx, c_idx + n + 1, idx) - c_idx;
		long d = idx - c_idx[k - 1];
		return c[k - 1] + d * (d + 1) / 2;
	};

	for (int i = 0; i < q; i++) {
		int s;
		scanf("%d", &s);
		int l = 0, r = len + 1;
		while (r - l > 1) {
			int mid = (l + r) / 2;
			if (total(mid) >= s) {
				r = mid;
			} else {
				l = mid;
			}
		}
		if (r > len) {
			r = -1;
		}
		printf("%d\n", r);
	}
}