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


int n;
vector<string> a;
int maxi = 0;
vector<int> res;
vector<bool> used;
vector<vector<int>> dp(n, vector<int> (n, -1));
vector<int> ans;
int mnsize = 1e9;
clock_t t;
int solve(string a, string b){
    int mx = 0;
    string x = "";
    for(int i = 0; i < b.size(); ++i){
        x.push_back(b[i]);
        if(x.size() > a.size())
            break;
        if(a.substr(a.size() - x.size(), x.size()) == x)
            mx = x.size();
    }
    return mx;
}


void sum(int u){
    int pos = 0;
    int mx = -1;
    bool flag = false;
    for(int v = 0; v < n; ++v){
        if(!used[v] && dp[u][v] > mx){
            pos = v;
            mx = dp[u][v];
            flag = true;
        }
    }
    if(!flag)
        return;
    used[pos] = true;
    maxi += a[pos].size() - dp[u][pos];
    res.push_back(pos);
    sum(pos);
}


void rec(int u, int sz, int c){
    clock_t b = clock();

    if (double(b - t)/CLOCKS_PER_SEC > 2) {
        cout << mnsize << endl;
        return;
    }
    if(sz >= mnsize)
        return;
    if(c == n){
        cout << ans.size() << endl;
        ans = res;
        mnsize = sz;
        return;
    }
    for(int v = 0; v < n; ++v){
        if(!used[v]){
            res.push_back(v);
            used[v] = true;
            rec(v, sz + a[v].size() - dp[u][v], c + 1);
            res.pop_back();
            used[v] = false;
        }
    }
}

int main() {
    t = clock();
    cin >> n;
    a.resize(n);
    ans.resize(n);
    for(int i = 0; i < n; ++i)
        cin >> a[i];
    dp.resize(n, vector<int>(n));
    for(int i = 0; i < n; ++i){
        for(int j = 0; j < n; ++j){
            if(i != j){
                dp[i][j] = solve(a[i], a[j]);
            }
        }
    }
    int st = 0;
    for(int i = 0; i < n; ++i){
        res.clear();
        res.push_back(i);
        maxi = a[i].size();
        used.assign(n, false);
        used[i] = true;
        sum(i);
        if(maxi < mnsize){
            st = i;
            mnsize = maxi;
            ans = res;
        }
    }
    //cout << ans.size() << endl;
    for(int i = 0; i < n; ++i){
        res.clear();
        res.push_back(i);
        maxi = a[i].size();
        used.assign(n, false);
        used[i] = true;
        rec(i, a[i].size(), 1);
    }
    string s = a[ans[0]];
    for(int i = 1; i < n; ++i){
        string xs = a[ans[i]].substr(dp[ans[i - 1]][ans[i]]);
        s += xs;
    }
    cout << s << endl;
}