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#include<bits/stdc++.h>
#define ll long long
#define pii pair<int, int>
#define st first
#define nd second
#define turbo ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define pb push_back
#define vi vector<int>
#define vvi vector<vi>
#define qi queue<int>
#define ld long double

using namespace std;

/*---------------------------------------------------------///CODE///---------------------------------------------------------*/

const ll MAX = 1LL << 30;
const ll MOD = 1e9 + 7;

struct Node
{
    pair<ll, ll> value;
    Node *l, *r;
    Node(): l(NULL), r(NULL) 
    {
        value = {0, 0};
    }
};

ll getvalue(Node* v, bool x)
{
    if(v == NULL)
        return 0;
    if(!x) return (v -> value).st;
    else return (v -> value).nd;
}

Node* getl(Node* v)
{
    if(v -> l == NULL)
        return v -> l = new Node();
    return v -> l;
}

Node* getr(Node* v)
{
    if(v -> r == NULL)
        return v -> r = new Node();
    return v -> r;
}

ll Query(ll a, ll b, bool x, ll lo, ll hi, Node* v)
{
    if(a > b)
        return 0;
    if(lo >= a && hi <= b)
        return getvalue(v, x);
    if(lo > b || hi < a)
        return 0;
    
    ll mid = (lo + hi) >> 1;

    return (Query(a, b, x, lo, mid, getl(v)) + Query(a, b, x, mid + 1, hi, getr(v))) % MOD;
}

void Update(ll p, bool x, ll lo, ll hi, Node* v, ll ile)
{
    if(lo == hi && lo == p)
    {
        if(!x) (v -> value).st = ((v -> value).st + ile) % MOD;
        else (v -> value).nd = ((v -> value).nd + ile) % MOD;  
        return;
    }
    if(lo > p || hi < p)
        return;

    
    ll mid = (lo + hi) >> 1;

    Update(p, x, lo, mid, getl(v), ile);
    Update(p, x, mid + 1, hi, getr(v), ile);
    v -> value = {(getvalue(v -> l, 0) + getvalue(v -> r, 0)) % MOD, (getvalue(v -> l, 1) + getvalue(v -> r, 1)) % MOD};
}

int main()
{
    turbo

    Node* Tree = new Node();

    int n; cin >> n;
    ll start = 0;

    vector<ll> v(n);

    for(int i = 0; i < n; i++)
        cin >> v[i];

    Update(v[0], v[0] % 2, 0, MAX - 1, Tree, 1);
    
    for(int i = 1; i < n; i++)
    {
        ll sum = (Query(start, MOD - 1, start % 2, 0, MAX - 1, Tree) + Query(0, start - 1, (start % 2) ^ 1, 0, MAX - 1, Tree)) % MOD;
        start = (start - v[i] + MOD) % MOD;
        Update((start + v[i]) % MOD, ((start + v[i]) % MOD) % 2, 0, MAX - 1, Tree, sum);
    }
    
    cout << (Query(start, MOD - 1, start % 2, 0, MAX - 1, Tree) + Query(0, start - 1, (start % 2) ^ 1, 0, MAX - 1, Tree)) % MOD;

    return 0;
}