#include<bits/stdc++.h>
using namespace std;
const int maxn = 25000;
int n;
vector<char> res;
struct TRIE{
struct NODE{
int nxt[26], cnt, len;
inline NODE(){
fill(nxt, nxt + 26, -1);
cnt = len = 0;
}
}; vector<NODE> node;
inline TRIE(){
node.push_back(NODE());
}
inline void insert(const string& s){
int pos = 0;
for (int i = 0; i < s.size(); ++i){
int c = s[i] - 'a';
if (node[pos].nxt[c] == -1){
node[pos].nxt[c] = node.size();
node.push_back(NODE());
}
pos = node[pos].nxt[c];
node[pos].len = max(node[pos].len, (int)s.size());
}
node[pos].cnt++;
return;
}
inline void DFS(int pos){
if (node[pos].cnt > 0) res.push_back('P');
vector<pair<int, int>> v;
for (int i = 0; i < 26; ++i) if (node[pos].nxt[i] != -1){
v.push_back({node[node[pos].nxt[i]].len, i});
}
sort(v.begin(), v.end());
for (pair<int, int> x : v){
res.push_back((char)('a' + x.second));
DFS(node[pos].nxt[x.second]);
}
res.push_back('-');
return;
}
} trie;
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n;
for (int i = 0; i < n; ++i){
string s; cin >> s;
trie.insert(s);
}
trie.DFS(0);
while(res.back() == '-') res.pop_back();
cout << res.size() << '\n';
for (char x : res) cout << x << '\n';
return 0;
}
