#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define all(vr) vr.begin(),vr.end()
#define vi vector<int>
#define vll vector<ll>
const int N=1e5+10;
struct node
{
map<char,node*> nxt;
int mx_len;
vector<pair<int,char>> order;
};
node* root=new node();
void add_string(string s)
{
node* cur=root;
for (char c : s)
{
if (cur->nxt[c]==NULL) cur->nxt[c]=new node();
cur=cur->nxt[c];
}
cur->mx_len=s.length();
}
void dfs(node *cur)
{
if (cur->nxt.empty()) return;
cur->mx_len=0;
vector<pair<int,char>> &vt=cur->order;
for (pair<char,node*> p : cur->nxt)
{
dfs(p.se);
cur->mx_len=max(cur->mx_len,p.se->mx_len);
vt.eb(p.se->mx_len,p.fi);
}
sort(all(vt));
}
vector<char> ans;
void print(node *cur)
{
for (pair<int,char> p : cur->order)
if (p.se=='P') ans.eb(p.se);
else
{
ans.eb(p.se);
print(cur->nxt[p.se]);
ans.eb('-');
}
}
int main()
{
//freopen("ss.inp","r",stdin);
ios::sync_with_stdio(false);
cin.tie(0);
int n;
cin>>n;
for (int i=1;i<=n;i++)
{
string s;
cin>>s;
s+='P';
add_string(s);
}
dfs(root);
print(root);
while (ans.back()=='-') ans.pop_back();
cout<<ans.size()<<"\n";
for (char c : ans) cout<<c<<"\n";
return 0;
}
