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#if defined(EMBE_DEBUG) && !defined(NDEBUG)
#include "embe-debug.hpp"
#else
#define LOG_INDENT(...) do {} while (false)
#define LOG(...) do {} while (false)
#define DUMP(...) do {} while (false)
#endif

#include <algorithm>
#include <array>
#include <iostream>
#include <vector>
using namespace std;

namespace {

constexpr auto mod = 1'000'000'007;

struct Node {
  int low = 0;
  int high = 0;
  array<int, 2> sum = {0, 0};
};

struct State {
  int extra = 0;
  int n;

  vector<int> data;
  vector<Node> tree;

  void reserve(int x)
  {
    x -= extra;
    if (x < 0) x += mod;
    data.emplace_back(x);
  }

  void update_sum(int k)
  {
    tree[k].sum[0] = (tree[2 * k].sum[0] + tree[2 * k + 1].sum[0]) % mod;
    tree[k].sum[1] = (tree[2 * k].sum[1] + tree[2 * k + 1].sum[1]) % mod;
  }

  void reset()
  {
    extra = 0;
    sort(data.begin(), data.end());
    data.erase(unique(data.begin(), data.end()), data.end());
    n = 1;
    while (n <= int(data.size())) n *= 2;
    tree.resize(2 * n);
    for (int i = 0; i < int(data.size()); ++i) {
      tree[n + i].low = tree[n + i].high = data[i];
    }
    for (int i = data.size(); i < n; ++i) {
      tree[n + i].low = tree[n + i].high = mod;
    }
    for (int i = n - 1; i > 0; --i) {
      tree[i].low = tree[2 * i].low;
      tree[i].high = tree[2 * i + 1].high;
      update_sum(i);
    }
  }

  void add(int x, int v)
  {
    x -= extra;
    if (x < 0) x += mod;
    int i = lower_bound(data.begin(), data.end(), x) - data.begin();
    int k = n + i;
    tree[k].sum[x % 2] += v;
    tree[k].sum[x % 2] %= mod;
    while (k > 1) {
      k /= 2;
      update_sum(k);
    }
  }

  void rotate(int dx)
  {
    extra += dx;
    extra %= mod;
  }

  int sum_even() const
  {
    int res = 0;
    res += sum(mod - extra, mod, (extra + 1) % 2);
    res += sum(0, mod - extra, extra % 2);
    res %= mod;
    return res;
  }

  int sum(int a, int b, int m, int k=1) const
  {
    if (k >= 2 * n) return 0;
    if (a > tree[k].high || b <= tree[k].low) return 0;
    if (a <= tree[k].low && b > tree[k].high) return tree[k].sum[m];
    int res = 0;
    res += sum(a, b, m, 2 * k);
    res += sum(a, b, m, 2 * k + 1);
    return res % mod;
  }
};

}

int main()
{
  iostream::sync_with_stdio(false);
  cin.tie(nullptr);

  int n;
  cin >> n;
  vector<int> data(n);
  for (int& x: data) cin >> x;

  int sum = 0;
  for (int x: data) {
    sum += x;
    sum %= mod;
  }
  State state;
  state.reserve(data[0]);
  for (int i = 1; i < n; ++i) {
    state.reserve(0);
    state.rotate(data[i]);
  }
  state.reset();
  state.add(data[0], 1);
  for (int i = 1; i < n; ++i) {
    state.add(0, state.sum_even());
    state.rotate(data[i]);
  }

  cout << state.sum_even() << endl;

  return 0;
}