#include <iostream>
#include <fstream>
#include <cstring>
#include <algorithm>

using namespace std;

const int Nmax = 18;
const int Lmax = 1e5 + 2;
const int inf = 0x3f3f3f3f;

char S[Nmax][Lmax];
int C[Nmax][Nmax];
int D[1 << Nmax][Nmax];
int pi[Lmax];
int lg[Nmax];
int N;

void build_prefix( char s[] )
{
    int lgprefix = 0;
    int n = strlen( s + 1 );

    pi[1] = 0;

    for ( int i = 2; i <= n; ++i )
    {
        while ( lgprefix && s[i] != s[lgprefix + 1] )
                lgprefix = pi[lgprefix];

        if ( s[i] == s[lgprefix + 1] )
                lgprefix++;

        pi[i] = lgprefix;
    }
}

int KMP_cost( char patt[], char text[] )
{
    int n = strlen( patt + 1 );
    int m = strlen( text + 1 );

    int lgprefix = 0;

    for ( int i = 1; i <= m; ++i )
    {
        while ( lgprefix && text[i] != patt[lgprefix + 1] )
                lgprefix = pi[lgprefix];

        if ( text[i] == patt[lgprefix + 1] )
                lgprefix++;

        if ( lgprefix == n )
                return n;
    }

    return lgprefix;
}

int cycle( int stare, int nodAnterior )
{
    if ( D[stare][nodAnterior] != -1 )
            return D[stare][nodAnterior];

    if ( stare == ( 1 << N ) - 1 )
    {
        return 0;
    }
    else
    {
        D[stare][nodAnterior] = -inf;

        for ( int i = 0; i < N; ++i )
        {
            if ( ( stare & ( 1 << i ) ) == 0 )
            {
                int ans = C[nodAnterior][i] + cycle( stare ^ ( 1 << i ), i );

                if ( ans > D[stare][nodAnterior] )
                {
                    D[stare][nodAnterior] = ans;
                }
            }
        }

        return D[stare][nodAnterior];
    }
}

int sol[Nmax];
int P[Nmax];

void perm()
{
    for ( int i = 0; i < N; ++i )
            P[i] = i;

    int maxim = 0;

    do
    {
        int sum = 0;

        for ( int i = 0; i < N - 1; ++i )
                sum += C[ P[i] ][ P[i + 1] ];

        if ( sum > maxim )
        {
            for ( int i = 0; i < N; ++i )
                    sol[i] = P[i];

            maxim = sum;
        }

    } while ( next_permutation( P, P + N ) );

    int sum = 0;

    for ( int i = 0; i < N; ++i )
            sum += strlen( S[i] + 1 );

    cout << sum - maxim << endl;
}

int main()
{
    ifstream cin("adn.in");

    cin >> N;

    for ( int i = 0; i < N; ++i )
    {
        cin >> ( S[i] + 1 );

        lg[i] = strlen( S[i] + 1 );
    }

    for ( int i = 0; i < N; ++i )
    {
        build_prefix( S[i] );

        for ( int j = 0; j < N; ++j )
        {
            if ( i != j )
            {
                int kmp = KMP_cost( S[i], S[j] );

                if ( kmp == lg[i] )
                {
                    memcpy( S[i], S[N - 1], sizeof( S[N - 1] ) );
                    lg[i] = lg[N - 1];
                    memset( S[N - 1], 0, sizeof( S[N - 1] ) );

                    N--;
                    i--;
                    break;
                }
            }
        }
    }

    for ( int i = 0; i < N; ++i )
    {
        build_prefix( S[i] );

        for ( int j = 0; j < N; ++j )
                if ( i != j )
                    C[j][i] = KMP_cost( S[i], S[j] );
    }

    // for ( int i = 0; i < ( 1 << N ); ++i )
     //       for ( int j = 0; j < N; ++j )
       //         D[i][j] = -1;

    // for ( int i = 0; i < N; ++i, cout << endl )
        //    for ( int j = 0; j < N; ++j )
           //         cout << C[i][j] << " ";

    /**for ( int i = 0; i < N; ++i )
    {
        cout << cycle( 1 << i, i ) << "\n";
    }

    cout << endl;
    **/
    perm();

    ofstream cout("adn.out");

     for ( int i = 0; i < N - 1; ++i )
    {
        int cat = strlen( S[ sol[i] ] + 1 ) - C[ sol[i] ][ sol[i + 1] ];

        for ( int j = 1; j <= cat; ++j )
                cout << S[ sol[i] ][j];
    }

    for ( int j = 1; j <= strlen( S[ sol[N - 1] ] + 1 ); ++j )
            cout << S[ sol[N - 1] ][j];

    return 0;
}