ll @n, @q, len = 0;
ll @a[n];
for (ll i = 0; i < n; i++) {
	len += a[i];
}
ll c_idx[n+1], c[n+1];
c_idx[0] = 0;
c[0] = 0;
rep (i,n) {
	c_idx[i + 1] = c_idx[i] + a[i];
	c[i + 1] = c[i] + a[i] * (a[i] + 1) / 2;
}
rep (q) {
	ll @s;
	if (c[n] < s) {
		wt(-1);
		continue;
	}
	ll l = lower_bound(c, c + n + 1, s) - c;
	wt(c_idx[l - 1] + long(std::sqrt(2 * (s - c[l - 1]) + 0.5)));
}