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#include <bits/stdc++.h>

using namespace std;

const int N = 1048576;
const int M = 1000000007;

int n,l,a;
int t[300005];
int dp[300005];
int tree1[2097152];
int tree2[2097152];
vector <int> v;
map <int,int> m;

void add1(int w, int val)
{
    w+=N-1;
    while (w>0)
    {
        tree1[w]+=val;
        tree1[w]%=M;
        w/=2;
    }
}

void add2(int w, int val)
{
    w+=N-1;
    while (w>0)
    {
        tree2[w]+=val;
        tree2[w]%=M;
        w/=2;
    }
}

int query1(int w, int p, int k, int x, int y)
{
    if (x>k || y<p) return 0;
    if (x<=p && k<=y) return tree1[w];
    return (query1(w*2,p,(p+k)/2,x,y)+query1(w*2+1,(p+k)/2+1,k,x,y))%M;
}

int query2(int w, int p, int k, int x, int y)
{
    if (x>k || y<p) return 0;
    if (x<=p && k<=y) return tree2[w];
    return (query2(w*2,p,(p+k)/2,x,y)+query2(w*2+1,(p+k)/2+1,k,x,y))%M;
}

void wypisz()
{
    cout << endl << endl;
    for (int i=1; i<2*N; i++)
    {
        cout << i << " " << tree2[i] << endl;
    }
    cout << endl;
}

int main()
{
    scanf("%d",&n);
    for (int i=1; i<=n; i++)
    {
        scanf("%d",&t[i]);
        t[i]+=t[i-1];
        t[i]%=M;
        //cout << t[i] << " ";
        v.push_back(t[i]);
    }
    //cout << endl;
    v.push_back(0);
    sort(v.begin(),v.end());
    for (auto i : v)
    {
        if (m[i]) continue;
        l++;
        if (l%2 != i%2) l++;
        m[i]=l;
    }
    add2(2,1);
    for (int i=1; i<=n; i++)
    {
        a=m[t[i]];
        //cout << a << endl;
        if (a&1)
        {
            dp[i]=query1(1,1,N,1,a)+query2(1,1,N,a,l);
            dp[i]%=M;
            add1(a,dp[i]);
        }
        else
        {
            dp[i]=query2(1,1,N,1,a)+query1(1,1,N,a,l);
            dp[i]%=M;
            add2(a,dp[i]);
        }
        //wypisz();
        //cout << dp[i] << endl;
    }
    printf("%d\n",dp[n]);
}