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#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
	ios_base::sync_with_stdio(0);

	int N;
	cin >> N;

	vector<int> c;
	c.reserve(N);

	for (int i = 0; i < N; i++) {
		int a;
		cin >> a;
		c.push_back(a);
	}

	sort(c.begin(), c.end());

	unsigned long long cnt = 1;
	int last = *c.rbegin();
	vector<unsigned long long> v(last, 0);

	v[0] = 1;

	const int MOD = 1000000007;

	unsigned long long total = 0;
	for (int i = 0; i < N; i++) {
		int candies = c[i];

		for (int j = 0; j < last && j < candies-1; j++) {
			cnt = (cnt + MOD - v[j]) % MOD;
			v[j] = 0;
		}

		for (int j = last-1; j >= candies; j--)
			v[j] = (v[j] + v[j-candies]) % MOD;

		total = (total + cnt) % MOD;
		cnt = (cnt*2) % MOD;
	}

	cout << total << endl;

	return 0;
}