#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* da = new long[n+1];
    da[1] = 1;
    for (int i = 2; i<=n; i++){
        da[i] = da[i-1] * 2;
    }
    
    int k = 0;
    unsigned long result=1;
    for (int i = 1; i< n; i++){
       k++;
       if (m[i] < m[i-1]){
           result *= da[k];
           k = 0;
       }
       if (i == n-1){
           k++;
           result *= da[k];
       }
       
    }
    // your code goes here
    cout << result <<endl;
    
    return 0;
}