#include <bits/stdc++.h>
using namespace std;
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>
// using namespace __gnu_pbds;
// template<class x>
// using ordered_set = tree<x, null_type,less<x>, rb_tree_tag,tree_order_statistics_node_update>;
// template<class x>
// using ordered_multiset = tree<x, null_type,less_equal<x>, rb_tree_tag,tree_order_statistics_node_update>;
#define int long long
#define mod 1'000'000'007
struct node {
node *adj[26];
int cnt_end;
int max_dep, dep;
node () {
for(int i = 0; i < 26; i++){
adj[i] = 0;
}
cnt_end = 0;
dep = 0;
max_dep = 0;
}
};
node *root = new node;
void inser(string s){
node *cur = root;
for(auto c : s){
if(!cur -> adj[c - 'a']){
cur -> adj[c - 'a'] = new node;
}
cur = cur -> adj[c - 'a'];
}
cur -> cnt_end++;
}
void dfs(node *cur, int p){
cur -> dep = p + 1;
cur -> max_dep = cur -> dep;
for(int i = 0; i < 26; i++){
if(cur -> adj[i]){
dfs(cur -> adj[i], cur -> dep);
cur -> max_dep = max(cur -> adj[i] -> max_dep, cur -> max_dep);
}
}
}
string ans = "";
void dfs2(node *cur){
while(cur -> cnt_end--){
ans += 'P';
}
int m = -1;
for(int i = 0; i < 26; i++){
if(cur -> adj[i]){
if(m == -1 || cur -> adj[i] -> max_dep > cur -> adj[m] -> max_dep){
m = i;
}
}
}
for(int i = 0; i < 26; i++){
if(cur -> adj[i] && i != m){
ans += (char)(i + 'a');
dfs2(cur -> adj[i]);
ans += '-';
}
}
if(m != -1){
ans += (char)(m + 'a');
dfs2(cur -> adj[m]);
ans += '-';
}
}
signed main()
{
ios_base::sync_with_stdio(false);cin.tie(NULL);
int n;
cin>>n;
for(int i = 0; i < n; i++){
string s;
cin>>s;
inser(s);
}
dfs(root, 0);
dfs2(root);
while(ans.back() == '-'){
ans.pop_back();
}
cout<<ans.size()<<'\n';
for(int i = 0; i < ans.size(); i++){
cout<<ans[i]<<'\n';
}
return 0;
}
