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

#define sim template <class c
#define ris return *this
#define dor > debug &operator<<
#define eni(x)                                                                    \
    sim > typename enable_if<sizeof dud<c>(0) x 1, debug &>::type operator<<(c i) \
    {
sim > struct rge
{
    c b, e;
};
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c *x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug
{
#ifdef XOX
    ~debug()
    {
        cerr << endl;
    }
    eni(!=) cerr << boolalpha << i;
    ris;
} eni(==) ris << range(begin(i), end(i));
}
sim, class b dor(pair<b, c> d)
{
    ris << "" << d.first << " --> " << d.second << "";
}
sim dor(rge<c> d)
{
    *this << "[";
    for (auto it = d.b; it != d.e; ++it)
        *this << ", " + 2 * (it == d.b) << *it;
    ris << "]";
}
#else
    sim dor(const c &)
    {
        ris;
    }
#endif
}
;

#define imie(...) "" << #__VA_ARGS__ " = " << (__VA_ARGS__) << ", "
#define pb push_back
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define f first
#define s second

#define sz(x) (x).size()
#define all(x) (x).begin(), (x).end()
#define vt vector

using ll = long long;
using pi = pair<int, int>;
using pll = pair<ll, ll>;

using vi = vt<int>;
using vvi = vt<vi>;
using vll = vt<ll>;
using vvll = vt<vll>;
using vs = vt<string>;
using vpi = vt<pi>;
using vvpi = vt<vpi>;
using vpll = vt<pll>;
using vvpll = vt<vpll>;

const int mod = 1e9 + 7;
const int nax = 1e6 + 9;

int a[nax];
int dp[nax];
int n;
void submod(int &a, int b)
{
    a -= b;
    if (a < 0)
        a += mod;
}
void addmod(int &a, int b)
{
    a += b;
    if (a >= mod)
        a -= mod;
}
struct node
{
    int l, r, mid;
    int even = 0, odd = 0;
    node *left = nullptr, *right = nullptr;
    node(int L, int R)
    {
        l = L, r = R, mid = l + (r - l) / 2;
    }
    void add(int pos, int val)
    {
        if (l == r)
        {
            if (pos % 2)
                addmod(odd, val);
            else
                addmod(even, val);
            return;
        }
        if (pos <= mid)
        {
            if (left == nullptr)
                left = new node(l, mid);
            left->add(pos, val);
        }
        else
        {
            if (right == nullptr)
                right = new node(mid + 1, r);
            right->add(pos, val);
        }
        even = odd = 0;
        if (left != nullptr)
        {
            addmod(even, left->even);
            addmod(odd, left->odd);
        }
        if (right != nullptr)
        {
            addmod(even, right->even);
            addmod(odd, right->odd);
        }
    }
    int sum(int lq, int rq, int eo)
    {
        if (l > rq || r < lq)
            return 0;
        if (lq <= l && r <= rq)
        {
            if (eo)
                return odd;
            else
                return even;
        }
        int ans = 0;
        if (left != nullptr)
            addmod(ans, left->sum(lq, rq, eo));
        if (right != nullptr)
            addmod(ans, right->sum(lq, rq, eo));
        return ans;
    }
};
int main()
{
    node tree(0, mod);
    cin >> n;
    for (int i = 1; i <= n; i++)
        cin >> a[i];
    tree.add(0, 1);
    int sum = 0;
    for (int i = 1; i <= n; i++)
    {
        addmod(sum, a[i]);
        int eo = sum % 2;
        addmod(dp[i], tree.sum(0, sum, eo));
        if (sum < mod - 1)
            addmod(dp[i], tree.sum(sum + 1, mod - 1, eo ^ 1));
        if (dp[i])
            tree.add(sum, dp[i]);
    }
    cout << dp[n];
}