#include <bits/stdc++.h>

int main() {
	int n, q, len = 0;
	scanf("%d%d", &n, &q);
	std::vector<int> a(n);
	for (int i = 0; i < n; i++) {
		scanf("%d", &a[i]);
		len += a[i];
	}
	std::vector<int64_t> c(len + 1);
	int idx = 1;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < a[i]; j++) {
			c[idx] = j + 1;
			idx++;
		}
	}
	for (int i = 0; i < len; i++) {
		c[i + 1] += c[i];
	}
	for (int i = 0; i < q; i++) {
		int s;
		scanf("%d", s);
		auto it = lower_bound(c.begin(), c.end(), s);
		if (it == c.end()) {
			puts("-1");
		} else {
			printf("%d\n", it - c.begin());
		}
	}
}