#include<iostream>

#include<cstdio>

#include<cmath>

#include<cstdlib>

#include<cstring>

#include<algorithm>

using namespace std;

int read()

{

    int x=,f=;char c=getchar();

    while (c<''||c>'') {if (c=='-') f=-;c=getchar();}

    while (c>=''&&c<='') x=(x<<)+(x<<)+(c^),c=getchar();

    return x*f;

}

#define N 12

#define M 52

int n,len[N],d[N][N];

char s[N][M];

struct str

{

    int n;char s[N*M];

    bool operator <(const str&a) const

    {

        for (int i=;i<=n;i++)

        if (s[i]!=a.s[i]) return s[i]<a.s[i];

        return ;

    }

};

str get(int p,int q);

struct data

{

    int i,j,x,n,s[N+];

    bool operator <(const data&a) const

    {

        if (x!=a.x) return x<a.x;

        return get(i,j)<get(a.i,a.j);

    }

}f[<<N][N];

str get(int p,int q)

{

    int n=f[p][q].n;

    str v;memset(v.s,,sizeof(v.s));

    int x=len[f[p][q].s[]];

    for (int i=;i<=len[f[p][q].s[]];i++) v.s[i]=s[f[p][q].s[]][i];

    for (int i=;i<=n;i++)

        for (int j=d[f[p][q].s[i-]][f[p][q].s[i]]+;j<=len[f[p][q].s[i]];j++)

        v.s[++x]=s[f[p][q].s[i]][j];

    v.n=x;

    return v;

}

int main()

{

#ifndef ONLINE_JUDGE

    freopen("bzoj1195.in","r",stdin);

    freopen("bzoj1195.out","w",stdout);

    const char LL[]="%I64d\n";

#else

    const char LL[]="%lld\n";

#endif

    n=read();

    for (int i=;i<n;i++) scanf("%s",s[i]+),len[i]=strlen(s[i]+);

    for (int i=;i<n;i++)

        for (int j=;j<n;j++)

        if (i!=j)

            for (int k=;k<=len[i];k++)

            {

                bool flag=;

                for (int x=;x<=len[j]&&k+x-<=len[i];x++)

                if (s[i][k+x-]!=s[j][x]) {flag=;break;}

                if (flag) {d[i][j]=min(len[i]-k+,len[j]);break;}

            }

    for (int i=;i<(<<n);i++)

        for (int j=;j<n;j++)

        f[i][j].x=,f[i][j].i=i,f[i][j].j=j;

    for (int i=;i<n;i++) f[<<i][i].x=len[i],f[<<i][i].s[]=i,f[<<i][i].n=;

    for (int i=;i<(<<n);i++)

        for (int j=;j<n;j++)

        if (i&(<<j))

            for (int k=;k<n;k++)

            if (!(i&(<<k)))

                if (d[j][k]==len[k]) f[i|(<<k)][j]=min(f[i|(<<k)][j],f[i][j]),f[i|(<<k)][j].i=i|(<<k);

                else

                {

                    data t=f[i][j];

                    f[i][j].x+=len[k]-d[j][k];

                    f[i][j].s[++f[i][j].n]=k;

                    f[i|(<<k)][k]=min(f[i|(<<k)][k],f[i][j]),f[i|(<<k)][k].i=i|(<<k),f[i|(<<k)][k].j=k;

                    f[i][j]=t;

                }

    for (int i=;i<n;i++) f[(<<n)-][]=min(f[(<<n)-][],f[(<<n)-][i]),f[(<<n)-][].j=;

    printf("%s",get((<<n)-,).s+);

    return ;

}