#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define dbg(...) 47
#endif
constexpr int N = 5e5 + 5;
int trie[N][26], cnt = 0;
bool is_end[N];
void insert(string s) {
int node = 0;
for (auto c : s) {
int j = c - 'a';
if (trie[node][j] == 0) {
trie[node][j] = ++cnt;
}
node = trie[node][j];
}
is_end[node] = 1;
}
int d[N];
void dfs_dist(int u) {
for (int i = 0; i < 26; i++) {
if (trie[u][i]) {
dfs_dist(trie[u][i]);
d[u] = max(d[u], d[trie[u][i]] + 1);
}
}
}
string k;
void dfs(int u) {
if (is_end[u]) {
k.push_back('P');
}
vector<array<int, 2>> v;
for (int i = 0; i < 26; i++) {
if (trie[u][i] == 0) continue;
v.push_back({d[trie[u][i]], i});
}
ranges::sort(v);
for (auto [_, i] : v) {
k.push_back(i + 'a');
dfs(trie[u][i]);
k.push_back('-');
}
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n;
cin >> n;
for (int i = 0; i < n; i++) {
string s;
cin >> s;
insert(s);
}
dfs_dist(0);
dfs(0);
while (k.back() == '-') k.pop_back();
cout << k.size() << '\n';
for (auto c : k) {
cout << c << '\n';
}
return 0;
}
