// UUID: 58c4a3be-dcf0-4a52-aaba-224f48e4677c
#include <bits/stdc++.h>
using namespace std;
#define ll int
#define fs first
#define sc second
#define pb push_back
#define pll pair<ll, ll>
#define vll vector<ll>
#define v2ll vector<vll>
#define pqll priority_queue<ll>
const ll maxn = 1e6;
ll n;
vector<array<ll, 26>> trie(maxn);
vll cnt(maxn);
ll nodes = 1;
vector<bool> vis(maxn);
vector<char> ans;
string maxs;
void insert(string s) {
ll cur = 1;
for (char c : s) {
if (!trie[cur][c-'a']) trie[cur][c-'a'] = ++nodes;
cur = trie[cur][c-'a'];
cnt[cur]++;
}
}
void dfs(ll p, ll d) {
vis[p] = true;
bool flag = false;
ll l = -1;
for (ll i = 0; i < 26; i++) {
ll u = trie[p][i];
if (!u) continue;
flag = true;
if (d < maxs.length() && i == maxs[d]-'a') {
l = i;
continue;
}
if (!vis[u]) {
char c = i+'a';
ans.pb(c);
dfs(u, d+1);
ans.pb('-');
}
}
if (l != -1) {
ll u = trie[p][l];
if (!vis[u]) {
char c = l+'a';
ans.pb(c);
dfs(u, d+1);
ans.pb('-');
}
}
if (!flag) ans.pb('P');
}
void solve()
{
cin >> n;
for (ll i = 0; i < n; i++) {
string s;
cin >> s;
if (s.length() > maxs.length()) maxs = s;
insert(s);
}
dfs(1, 0);
while(ans.back() == '-') ans.pop_back();
cout << ans.size() << '\n';
for (char c : ans) cout << c << '\n';
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL); cout.tie(NULL);
ll t = 1;
//cin >> t;
while(t--)
{
solve();
}
return 0;
}
