#include<bits/stdc++.h>
using namespace std;

typedef long long ll;

__int128 read() {
    __int128 x = 0, f = 1;
    char ch = getchar();
    while (ch >= '0' && ch <= '9') {
        x = x * 10 + ch - '0';
        ch = getchar();
    }
    return x * f;
}

void print(__int128 x) {
    if (x < 0) {
        putchar('-');
        x = -x;
    }
    if (x > 9) print(x / 10);
    putchar(x % 10 + '0');
}

signed main() {
    cin.tie(0)->sync_with_stdio(0);
    if (fopen("qoj_7695.inp", "r")) {
        freopen("qoj_7695.inp", "r", stdin);
        freopen("qoj_7695.out", "w", stdout);
    }

    // #ifdef LOCAL_MACHINE 
    //     if (fopen("task.inp", "r")) {
    //         freopen("task.inp", "r", stdin);
    //         freopen("task.out", "w", stdout);
    //     }
    // #endif

    int n; cin >> n;
    vector<int> a;
    for (int i = 1; i <= n; ++i) {
        __int128 x = read();
        int cur = 0;
        while (x > 1) {
            ++cur;
            x /= 2;
        }
        a.push_back(cur);
    }

    while (a.size() > 1) {
        // for (int i : a) cerr << i << " "; cerr << "\n";
        int mi = 1e9;
        for (int i : a) mi = min(mi, i);

        for (int i = 0; i + 1 < a.size(); ++i) if (a[i] == a[i + 1] && a[i] == mi) {
            a.erase(a.begin() + i); a.erase(a.begin() + i); a.insert(a.begin() + i, mi + 1); 
            break;
        }

        for (int i = 0; i < a.size(); ++i) if (a[i] == mi) {
            a.erase(a.begin() + i);
            break;
        }
    }

    __int128 res = 1;
    int val = a.back();
    while (val--) res *= 2;

    print(res);
}

// ඞඞඞඞඞ you sus