#include<bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using mint=modint1000000007;
using ll=long long;
using pp=pair<ll,ll>;
#define sr string 
#define vc vector
#define fi first
#define se second
#define rep(i,n) for(ll i=0;i<(ll)n;i++)
#define pb push_back
#define all(v) v.begin(),v.end()
#define pque priority_queue
#define bpc(a) __builtin_popcount(a)
struct modinv {
  int n; vector<mint> d;
  modinv(): n(2), d({0,1}) {}
  mint operator()(int i) {
    while (n <= i) d.push_back(-d[mint::mod()%n]*(mint::mod()/n)), ++n;
    return d[i];
  }
  mint operator[](int i) const { return d[i];}
} invs;
struct modfact {
  int n; vector<mint> d;
  modfact(): n(2), d({1,1}) {}
  mint operator()(int i) {
    while (n <= i) d.push_back(d.back()*n), ++n;
    return d[i];
  }
  mint operator[](int i) const { return d[i];}
} facts;
struct modfactinv {
  int n; vector<mint> d;
  modfactinv(): n(2), d({1,1}) {}
  mint operator()(int i) {
    while (n <= i) d.push_back(d.back()*invs(n)), ++n;
    return d[i];
  }
  mint operator[](int i) const { return d[i];}
} ifacts;
mint comb(int n, int k) {
  if (n < k || k < 0) return 0;
  return facts(n)*ifacts(k)*ifacts(n-k);
} 
int main(){
  int n;cin>>n;
  mint ans=1;
  int last=0; int t=0;
  rep(i,n){
    int a;cin>>a;
    t++;
    if(a==-1)continue;
    if((last&a)!=last){
      cout<<0;
      return 0;
    }
    int d=bpc(a)-bpc(last);
    last=a;
    a=bpc(a);
    mint res=0;
    rep(j,d+1){
      mint now=1; if(j&1)now=-1;
      now*=comb(d,j);
      mint g=mint(2).pow(a-j)-1;
      now*=g.pow(t);
      res+=now;
    }
    ans*=res;
    t=0;
  }
  cout<<ans.val();
}