#include <bits/stdc++.h>

using namespace std;

int main(){
    int n;
    cin >> n;
    vector<int> m(n);
    for(int m_i = 0; m_i < n; m_i++){
       cin >> m[m_i];
    }
    long long int answer=1;
    for(int ii=0;ii<n-1;ii++){
        answer=answer*2;
        answer=answer%1000000007;
    }
    cout << answer;
    return 0;
}