#include <bits/stdc++.h>
using namespace std;
#define FIO ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define ll long long
#define all(a) a.begin(), a.end()
#define endl '\n'
const int ALPHA = 26;
const char ZERO = 'a';
vector<char> ans;
struct Trie {
struct Node {
int child[ALPHA]{};
int max_depth = 0;
bool is_end = false;
};
vector<Node> trie;
Trie() {
trie.emplace_back();
}
void insert(const string &s) {
int idx = 0;
for(auto c : s)
{
int curr = c - ZERO;
if(!trie[idx].child[curr])
{
trie[idx].child[curr] = trie.size();
trie.emplace_back();
}
idx = trie[idx].child[curr];
}
trie[idx].is_end = 1;
}
int getDepth(int idx) {
int mx = 0;
for(int i = 0; i < ALPHA; i++)
{
if(trie[idx].child[i])
mx = max(mx, 1 + getDepth(trie[idx].child[i]));
}
return trie[idx].max_depth = mx;
}
void dfs(int idx) {
if(trie[idx].is_end)
{
ans.push_back('P');
}
vector<tuple<int, int, int>> ch;
for(int i = 0; i < ALPHA; i++)
{
if(trie[idx].child[i])
ch.push_back({trie[trie[idx].child[i]].max_depth, i, trie[idx].child[i]});
}
sort(all(ch));
for(auto &[len, c, i] : ch)
{
ans.push_back(c + ZERO);
dfs(i);
ans.push_back('-');
}
}
};
void solve() {
int n;
cin >> n;
Trie tr = Trie();
for (int i = 0; i < n; i++)
{
string s;
cin >> s;
tr.insert(s);
}
tr.getDepth(0);
tr.dfs(0);
while (!ans.empty() && ans.back() == '-') {
ans.pop_back();
}
cout << ans.size() << endl;
for (char c : ans) {
cout << c << endl;
}
}
int main()
{
FIO;
int t = 1;
// cin >> t;
while (t--)
solve();
return 0;
}
