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// Daniel Grzegorzewski
// while (clock()<=69*CLOCKS_PER_SEC)
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
// #pragma GCC optimize("Ofast")
// #pragma GCC target("avx,avx2,fma")

#define MP make_pair
#define PB push_back
#define ST first
#define ND second

using namespace __gnu_pbds;
using namespace std;

template <typename T>
using ordered_set =
    tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

//X.find_by_order(k); - zwraca iterator na k-ty element (numeracja od zerowego)
//X.order_of_key(k); - zwraca liczbę elementów ostro mniejszych niż k

typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VII;
typedef long long LL;

void init_ios() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
}

auto random_address = [] { char *p = new char; delete p; return uint64_t(p); };
 
const uint64_t SEED = chrono::steady_clock::now().time_since_epoch().count() * (random_address() | 1);
mt19937_64 rng(SEED);

const int N = 3*(int)1e5 + 3;
const int M = 64*N;
const int MOD = (int)1e9 + 7;
const int MOD2 = 2*MOD;

int n, nxt = 1, a[N], res[N];

struct Node {
  int l, r, ln, rn;
  PII sum;
} node[M];

void crl(Node& rt) {
  if (rt.ln == 0) {
    rt.ln = nxt;
    node[nxt].l = rt.l;
    node[nxt].r = (1LL*rt.l+rt.r)/2;
    node[nxt].ln = node[nxt].rn = 0;
    node[nxt].sum = {0, 0};
    ++nxt;
  }
}

void crr(Node& rt) {
  if (rt.rn == 0) {
    rt.rn = nxt;
    node[nxt].l = (1LL*rt.l+rt.r)/2+1;
    node[nxt].r = rt.r;
    node[nxt].ln = node[nxt].rn = 0;
    node[nxt].sum = {0, 0};
    ++nxt;
  }
}

void add(int& x, int y) {
  LL qwe = 1LL*x+y;
  if (qwe >= MOD2)
    qwe -= MOD2;
  x = qwe;
}

PII operator+(const PII& x, const PII& y) {
  LL qwe1 = 1LL*x.ST+y.ST;
  LL qwe2 = 1LL*x.ND+y.ND;
  if (qwe1 >= MOD2)
    qwe1 -= MOD2;
  if (qwe2 >= MOD2)
    qwe2 -= MOD2;
  return {qwe1, qwe2};
}


void upd(Node& rt) {
  rt.sum = {0, 0};
  if (rt.ln != 0)
    rt.sum = rt.sum+node[rt.ln].sum;
  if (rt.rn != 0)
    rt.sum = rt.sum+node[rt.rn].sum;
}


void add(int id, int v, int val) {
  auto& nd = node[id];
  if (nd.l == nd.r) {
    if (v%2 == 0)
      add(nd.sum.ST, val);
    else
      add(nd.sum.ND, val);
    return;
  }
  int mid = (1LL*nd.l+nd.r)/2;
  if (v <= mid) {
    crl(nd);
    add(nd.ln, v, val);
  }
  else {
    crr(nd);
    add(nd.rn, v, val);
  }
  upd(nd);
}

bool inters(PII p1, PII p2) {
  if (p1.ST > p2.ST)
    swap(p1, p2);
  return p1.ND >= p2.ST;
}

PII get(int id, int l, int r) {
  if (l > r)
    return {0, 0};
  auto& nd = node[id];
  if (r < nd.l || l > nd.r)
    return {0, 0};
  if (l <= nd.l && nd.r <= r)
    return nd.sum;
  int mid = (1LL*nd.l+nd.r)/2;
  PII res = {0, 0};
  if (inters({l, r}, {nd.l, mid})) {
    crl(nd);
    res = res+get(nd.ln, l, r);
  }
  if (inters({l, r}, {mid+1, nd.r})) {
    crr(nd);
    res = res+get(nd.rn, l, r);
  }
  return res;
}

int main() {
  init_ios();
  cin >> n;
  for (int i = 0; i < n; ++i)
    cin >> a[i];
  node[0].l = node[0].ln = node[0].rn = 0;
  node[0].r = (1LL<<31)-1;
  node[0].sum = {0, 0};
  int sum = 0;
  add(0, 0, 1);
  for (int i = n-1; i >= 0; --i) {
    add(sum, a[i]);
    bool pa = false;
    if (sum%2 == 0)
      pa = true;
    if (sum < MOD) {
      auto sm1 = get(0, 0, sum);
      auto sm2 = get(0, sum+1, MOD+sum);
      auto sm3 = get(0, MOD+sum+1, 2*MOD-1);
      if (pa) {
        add(res[i], sm1.ST);
        add(res[i], sm2.ND);
        add(res[i], sm3.ST);
      }
      else {
        add(res[i], sm1.ND);
        add(res[i], sm2.ST);
        add(res[i], sm3.ND);
      }
    }
    else {
      auto sm1 = get(0, 0, sum-MOD);
      auto sm2 = get(0, sum-MOD+1, sum);
      auto sm3 = get(0, sum+1, 2*MOD-1);
      if (pa) {
        add(res[i], sm1.ND);
        add(res[i], sm2.ST);
        add(res[i], sm3.ND);
      }
      else {
        add(res[i], sm1.ST);
        add(res[i], sm2.ND);
        add(res[i], sm3.ST); 
      }
    }
    add(0, sum, res[i]);
  }
  if (res[0] >= MOD)
    res[0] -= MOD;
  cout<<res[0]<<"\n";
}