#include <bits/stdc++.h>
#include <ext/pb_ds/detail/standard_policies.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define pb push_back
#define F first
#define S second
#define ll long long
#define FILE "t9"
#define ld long double
#define endl '\n'
#define pii pair <int, int>
#define last fedgfre
#define ull unsigned long long
//#define int long long

//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//#pragma GCC optimize("unroll-loops")

using namespace std;
using namespace __gnu_pbds;

#define kek pair <pii, int>

typedef tree <kek,null_type,less<kek>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;

const int N = 1e5 + 5;
const ll mod = 998244353;
const int rx[8] = {1, -1, 0, 0, 1, 1, -1, -1 };
const int ry[8] = {0, 0, 1, -1, 1, -1, 1, -1 };
const ld pi = acos(-1.0);
const int B = (int)sqrt(N);

const int kx[8] = {1, 1, -1, -1, 2, 2, -2, -2};
const int ky[8] = {2, -2, 2, -2, 1, -1, 1, -1};

mt19937 gen(chrono::high_resolution_clock::now().time_since_epoch().count());

int a[N];

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    //  srand(time(0));
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#else
    //  freopen(FILE".in", "r", stdin);
//   freopen(FILE".out", "w", stdout);
#endif // LOCAL
    int n;
    cin >> n;
    if (n == 1){
        cout << 1;
        return 0;
    }
    vector <pii> q;
    for (int i = 0; i < n; i += 2) {
        q.pb({i, i + 1});
    }
    int cnt = n / 2;
    for (int i = 0; i < n - 1; i++) cin >> a[i];
    int last = 0;
    while (cnt) {
        vector <int> win;
        int it = 0;
        for (int i = last; i < last + cnt; i++) {
            if (a[i] == 1) win.pb(q[it].F);
            else win.pb(q[it].S);
            it++;
        }
        q.clear();
        if (cnt == 1) {
            cout << win[0] + 1;
            return 0;
        }
        for (int i = 0; i < win.size(); i += 2) {
            q.pb({win[i], win[i + 1]});
        }
        last += cnt;
        cnt >>= 1;
    }
    return 0;
}