#include <bits/stdc++.h>
#define add emplace_back
using namespace std;
struct Node {
Node *child[26];
int ended, dep, vis;
Node () {
for (int i = 0;i < 26; i++) child[i] = nullptr;
ended = 0;
dep = 0;
vis = 0;
}
};
struct Trie {
Node *root;
Trie () {
root = new Node();
}
void insert (const string &s) {
Node *p = root;
for (auto c: s) {
if (p->child[c-'a'] == nullptr) p->child[c-'a'] = new Node();
p = p->child[c-'a'];
}
p->ended++;
}
void dfs (Node *p) {
p->dep = 1;
for (int i = 0;i < 26; i++) if (p->child[i] != nullptr) {
dfs (p->child[i]);
p->dep = max (p->dep, p->child[i]->dep + 1);
}
}
void type_and_print() {
int prv_del = 0;
vector<char> ans;
stack<Node*> st;
Node *s = root;
st.push(s);
while ((int)st.size()) {
Node *p = st.top();
p->vis = 1;
if (p->ended) {
for (int i = 0;i < p->ended; i++) ans.add('P');
}
int mx = -1, charmax = -1;
for (int i = 0;i < 26; i++) if (p->child[i] != nullptr) {
if (p->child[i]->vis == 0 && p->child[i]->dep > mx) {
mx = p->child[i]->dep;
charmax = i;
}
}
bool found = 0;
for (int i = 0;i < 26; i++) if (p->child[i] != nullptr) {
if (i == charmax) continue;
if (p->child[i]->vis == 0) {
st.push(p->child[i]);
ans.add((char)(i+'a'));
prv_del = 0;
found = 1;
break;
}
}
if (!found && mx > -1) {
prv_del = 0;
st.push(p->child[charmax]);
ans.add((char)(charmax+'a'));
}
else if (!found) {
st.pop();
ans.add('-');
prv_del++;
}
}
cout << (int)ans.size() - prv_del << "\n";
for (int i = 0;i < (int)ans.size() - prv_del; i++) cout << ans[i] << '\n';
}
};
int n;
string s;
Trie Wiki;
int main () {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n;
for (int i = 0;i < n; i++) {
cin >> s;
Wiki.insert(s);
}
Wiki.dfs(Wiki.root);
Wiki.type_and_print();
return 0;
}
