#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define SMTYON ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define hi cerr<<"HI\n";
/* -> NO CLEAN CODE HERE <- */
struct Node {
bool isEnd = false;
int len = 1;
int adj[26]{};
Node() { memset(adj, 0, sizeof adj); }
};
class Trie {
public:
vector<Node> h;
Trie() { h.emplace_back(); }
void insert(const string &s) {
int node = 0;
for (char c : s) {
int id = c - 'a';
if (!h[node].adj[id]) {
h[node].adj[id] = h.size();
h.emplace_back();
}
node = h[node].adj[id];
}
h[node].isEnd = true;
}
void start(int node) {
int mx = 0;
for (int c = 0; c < 26; c++) {
if (h[node].adj[c]) {
int child = h[node].adj[c];
start(child);
mx = max(mx, h[child].len);
}
}
h[node].len = mx+1;
}
void dfs(int u, vector<char> &ops) {
if (h[u].isEnd) ops.push_back('P');
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> q;
for (int c = 0; c < 26; c++) {
if (h[u].adj[c]) {
int child = h[u].adj[c];
q.push({h[child].len, c});
// ops.push_back('a' + c);
// dfs(h[u].adj[c], ops);
// ops.push_back('-');
}
}
while (!q.empty()) {
pair<int, int> p = q.top();
q.pop();
ops.push_back('a' + p.second);
dfs(h[u].adj[p.second], ops);
ops.push_back('-');
}
}
};
signed main() {
/* ^^^ */
SMTYON /* ^^^ */
// ->> practice makes perfect
int N;
cin >> N;
Trie t;
vector<string> words(N);
for (int i = 0; i < N; i++) {
cin >> words[i];
t.insert(words[i]);
}
vector<char> ops;
t.start(0);
t.dfs(0, ops);
int n = ops.size();
for (int i = n -1; i >= 0; i--) {
if (ops[i] == '-')ops.pop_back();
else break;
}
cout << ops.size() << endl;
for (auto x : ops) cout << x << endl;
}
