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#include <bits/stdc++.h>
using namespace std;

const int N = 3e5 + 10;
const long long mod = 1e9 + 7;

int n;
int tab[N];
long long pref[N];
long long d[2][N];	// 0*mod + p, 0*mod + np, 1*mod + p, 1*mod + np

bool cmp(int a, int b) {
	return pref[a] < pref[b];
}

void update(long long *fen, int x, long long ile) {
	if (x > n + 3) {
		return;
	}
	// cout << "halo " << x << " " << x + (x & (-x)) << " " << fen[x] << " " << ile << endl;
	fen[x] = (fen[x] + ile) % mod;
	update(fen, x + (x & (-x)), ile);
}

long long sum(long long *fen, int x) {
	// cout << "siema " << x << " " << fen[x] << endl;
	if (x == 0) {
		return 0;
	}
	return (fen[x] + sum(fen, x - (x & (-x)))) % mod;
}

long long get_sum(long long *fen, int a, int b) {
	// cout << "do widzenia" << endl;
	return (sum(fen, b) - sum(fen, a - 1) + mod) % mod;
}


int main() {
	scanf("%d", &n);
	for (int i = 1; i <= n; i++) {
		scanf("%d", &tab[i]);
	}
	for (int i = 1; i <= n; i++) {
		pref[i] = (pref[i - 1] + tab[i]) % mod;
	}
	vector<int> order;
	for (int i = 0; i <= n; i++) {
		order.push_back(i);
	}
	sort(order.begin(), order.end(), cmp);
	int last = -1;
	int curr = -1;
	for (auto v : order) {
		if (pref[v] != last) {
			last = pref[v];
			curr++;
			if (curr % 2 != pref[v] % 2) {
				curr++;
			}
		}
		pref[v] = curr;
	}
	update(d[0], 1, 1);
	long long res;
	for (int i = 1; i <= n; i++) {
		int par = pref[i] % 2;
		// printf("get_sum(%d, %d) -> %d", 1, (pref[i] + 2) / 2, par);
		res = (get_sum(d[par], 1, (pref[i] + 2) / 2) + get_sum(d[par ^ 1], (pref[i] + 2) / 2 + (pref[i] & 1), n + 3)) % mod;
		update(d[par], (pref[i] + 2) / 2, res);
		// res += get_sum(d[half ^ 1][par], (rest + 2) / 2 + 1, n) + get_sum(d[half ^ 1][par ^ 1], 0, )
	}
	printf("%lld\n", res);

	// for (int i = 0; i <= n; i++) {
	// 	printf("%lld ", pref[i]);
	// }
	// printf("\n");

}