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#include <iostream>
#include <unordered_map>
#include <vector>
#include <algorithm>

const long MAXT = 1l<<20;
const long MOD = 1000000007;
const int MAX = 300009;

class RT {
public:
  RT(){
    for (int i=0;i<2*MAXT;++i) {
      H[i].v[0] = 0;
      H[i].v[1] = 0;
    }
  }
  void Add(long p, int parity, long v) {
    p += MAXT;
    auto &hv = H[p].v[parity];
    hv = (hv+v)%MOD;
    p /= 2;
    while (p > 0) {
      //H[p].v[parity] = (H[2*p].v[parity] + H[2*p+1].v[parity]) % MOD;

      auto &hv = H[p].v[parity];
      hv = (hv+v)%MOD;

      p /= 2;
    }
  }
  long Query(long l, long r, int parity) {
    if (l>r) return 0;
    l += MAXT;
    r += MAXT;
    long s = H[l].v[parity];
    if (l!=r) s += H[r].v[parity];
    while (l/2 < r/2) {
      if (!(l&1)) s += H[l+1].v[parity];
      if (r&1) s += H[r-1].v[parity];
      l /= 2;
      r /= 2;
    }
    return s % MOD;
  }
private:
  struct Node {
    uint32_t v[2];
  };
  //std::unordered_map<uint32_t, Node> H;
  Node H[2*MAXT];
} rt;


long A[MAX];

int main() {
  std::ios_base::sync_with_stdio(0);
  long n;
  std::cin >> n;

  long o = 0;
  std::vector<uint32_t> V = {0, MOD-1};
  for (int i=0;i<n;++i) {
    std::cin >> A[i];
    // A[i] = i*1337l%MOD;
    o = (o+A[i]) % MOD;
    long x = MOD-o;
    V.push_back(x-1);
    V.push_back(x);
  }
  std::sort(V.begin(), V.end());
  V.erase(std::unique(V.begin(),V.end()), V.end());
  std::unordered_map<uint32_t, uint32_t> M;
  for (int i=0;i<V.size();++i) M[V[i]] = i;


  o = 0;
  long s = 0;
  for (int i=0;i<n;++i) {
    o = (o+A[i]) % MOD;

    long x = MOD-o;
    s = (
      rt.Query(M[0], M[x-1], o%2)
      + rt.Query(M[x], M[MOD-1], 1-o%2)
      + 1-o%2) % MOD;
    rt.Add(M[x%MOD], x%MOD%2, s);
  }
  std::cout << s << std::endl;
  return 0;
}