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#include <iostream>
#include <vector>
#include <algorithm>
typedef long long ll;
using namespace std;

ll mod = 1000000007;
int S = 1;
vector<ll> tree[2];

void add(int p, ll val, int nr)
{
    p += S;
    while (p)
    {
        tree[nr][p] = (tree[nr][p] + val)%mod;
        p>>=1;
    }
}

ll sum(int p, int q, int nr)
{
    p += S, q += S+1;
    ll r = 0;
    while (p < q)
    {
        if (p&1)
        {
            r = (r+tree[nr][p])%mod;
            p++;
        }
        if (q&1)
        {
            q--;
            r = (r+tree[nr][q])%mod;
        }
        p>>=1, q>>=1;
    }
    return r;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n; cin >> n;
    vector<ll> a(n+1), pref(n+1);
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i];
        pref[i] = (pref[i-1]+a[i])%mod;
    }
    sort(pref.begin(), pref.end());
    while (S < n+1) S<<=1;
    tree[0] = tree[1] = vector<ll>(2*S);
    ll ans = 0, asum = 0;
    add(0, 1, 0);
    for (int i = 1; i <= n; i++)
    {
        asum = (asum + a[i])%mod;
        int x = (lower_bound(pref.begin(), pref.end(), asum) - pref.begin());
        ans = (sum(0, x, asum%2) + sum(x+1, n, (asum%2)^1))%mod;
        add(x, ans, asum%2);
    }
    cout << ans;
}