#include <bits/stdc++.h>

#define endl '\n'
#define trace(x) cerr << #x << " = " << x << endl
#define sz(x) ((int)x.size())
#define all(x) x.begin(), x.end()

using namespace std;
template<class T, class T1> inline bool chkmax(T &x, const T1 &y) { return x < y ? x = y, true : false; }
template<class T, class T1> inline bool chkmin(T &x, const T1 &y) { return x > y ? x = y, true : false; }

const int MAXN = 1024;
const long long INF = (long long)1e18;

long long n;
vector<long long> a;

void read() {
    cin >> n;
    a.reserve(n);
    for (long long i = 0; i < n; i++) {
        long long ai;
        cin >> ai;
        a.emplace_back(ai);
    }
}

long long ans = INF;

void f(vector<long long> seq) {
    vector<long long> new_seq;
    long long len = 1;
    for (int i = 1; i < sz(seq); i++) {
        if (seq[i] == seq[i - 1]) len++;
        else {
            if (len > 1) {
                if (len & 1) {
                    new_seq.emplace_back(seq[i - 1] * (len - 1));
                    new_seq.emplace_back(seq[i - 1]);
                } else new_seq.emplace_back(seq[i - 1] * len);
            } else new_seq.emplace_back(seq[i]);
            len = 1;
        }
    }
    if (len > 1) {
        if (len & 1) {
            new_seq.emplace_back(seq.back() * (len - 1));
            new_seq.emplace_back(seq.back());
        } else new_seq.emplace_back(seq.back() * len);
    } else new_seq.emplace_back(seq.back());
    bool exec = false;
    if (new_seq != seq) {
        exec = true;
        f(new_seq);
    }
    new_seq.clear();
    len = 1;
    for (int i = 1; i < sz(seq); i++) {
        if (seq[i] == seq[i - 1]) len++;
        else {
            if (len > 1) {
                if (len & 1) {
                    new_seq.emplace_back(seq[i - 1]);
                    new_seq.emplace_back(seq[i - 1] * (len - 1));
                } else new_seq.emplace_back(seq[i - 1] * len);
            } else new_seq.emplace_back(seq[i]);
            len = 1;
        }
    }
    if (len > 1) {
        if (len & 1) {
            new_seq.emplace_back(seq.back());
            new_seq.emplace_back(seq.back() * (len - 1));
        } else new_seq.emplace_back(seq.back() * len);
    } else new_seq.emplace_back(seq.back());
    if (new_seq != seq) {
        exec = true;
        f(new_seq);
    }
    if (!exec) chkmin(ans, *min_element(all(seq)));
}

void solve() {
    f(a);
    cout << ans << endl;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    freopen("combine.in", "rt", stdin);
    freopen("combine.out", "wt", stdout);

    read();
    solve();

    return EXIT_SUCCESS;
}