/*

 ∧＿∧
( ･ω･｡)つ━☆・*。
⊂　 ノ 　　　・゜
しーＪ　　 Accepted

*/



// #pragma GCC optimize("O3")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

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

#define ll long long
#define all(x) begin(x), end(x)
#define x first
#define y second
#define int long long

using namespace std;
using namespace __gnu_pbds;

typedef long double ld;
template<typename T>
using kawaii_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

const ld PI = atan2(0, -1);

void seriy() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cout << fixed << setprecision(14);
    #ifdef _offline
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #endif
}

const int MAXN = 2e5 + 10;
const int MAXM = 600;
const int INF = 1e18 + 7;
const int BASE = 47;
const int MOD = 998244353;
const int MAXLOG = 61;
const ld EPS = 1e-8;

vector<vector<pair<int, int>>> g;
vector<int> dp, used, par;
map<pair<int, int>, string> mp;

int prefix_function (string s) {
	int n = (int) s.length();
	vector<int> pi (n);
	for (int i=1; i<n; ++i) {
		int j = pi[i-1];
		while (j > 0 && s[i] != s[j])
			j = pi[j-1];
		if (s[i] == s[j])  ++j;
		pi[i] = j;
	}
	return pi.back();
}

void dfs(int u) {
    used[u] = 1;
    for(auto v : g[u]) {
        if(!used[v.x]) {
            dfs(v.x);
        }
        if(used[v.x] != 1) {
            if(dp[u] < dp[v.x] + v.y) {
                dp[u] = dp[v.x] + v.y;
                par[u] = v.x;
            }
        }
    }
    used[u] = 2;
}

signed main() {
    seriy();
    int n;
    cin >> n;
    vector<string> s(n);
    int sum = 0;
    string ans = "";
    for(int i = 0; i < n; i++) {
        cin >> s[i];
        ans += s[i];
        sum += s[i].size();
    }
    g.resize(n);
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < n; j++) {
            if(i == j) continue;
            string k = s[i] + '#' + s[j];
            int pi = prefix_function(k);
            g[j].push_back({i, pi});
            string res = "";
            for(auto p : s[j]) {
                res += p;
            }

            k = s[j] + '#' + s[i];
            pi = prefix_function(k);
            g[i].push_back({j, pi});
        }
    }
    int mx = 0;

    for(int i = 0; i < n; i++) {
        dp.resize(n, 0);
        used.resize(n, 0);
        par.resize(n, -1);
        dfs(i);
        if(mx < dp[i]) {
            mx = dp[i];
            int cur = i;
            string kek = "";
            cerr << i << "  ";
            for(auto i : par) {
                cerr << i << " ";
            }
            cerr << '\n';
            // while(cur != -1) {
            //     kek += s[cur];
            //     cur = par[cur];
            // }
            // ans = kek;
        }
    }
    cout << ans;
    return 0;
}