// UUID: f9fcc435-f29b-4326-92b4-bcd3eb95d661
#include <bits/stdc++.h>
using namespace std;
const int MAXN=21*25000+1;
int trie[MAXN][26];
vector<int> word, utcs; vector<char> ki;
int cnt=1;
void add(string s){
int cur=0;
for(char z:s){
if(!trie[cur][z-'a']) trie[cur][z-'a']=cnt++;
cur=trie[cur][z-'a'];
if(word[cur]==- 1) word[cur]=0;
}
word[cur]++;
}
void add2(string s){
int cur=0;
for(char z:s){
if(!trie[cur][z-'a']) trie[cur][z-'a']=cnt++;
utcs[cur]=z-'a';
cur=trie[cur][z-'a'];
if(word[cur]==-1) word[cur]=0;
}
word[cur]++;
}
void dfs(int x){
for(int i=0; i<26; i++){
if(word[trie[x][i]]==-1||utcs[x]==i) continue;
ki.push_back(i+'a');
dfs(trie[x][i]);
}
if(utcs[x]!=-1){
ki.push_back(utcs[x]+'a');
dfs(trie[x][utcs[x]]);
}
if(word[x]>0) ki.push_back('P');
if(x)ki.push_back('-');
}
int main() {
int n; cin>>n;
vector<pair<int, string>> kak;
word.resize(n*21+1, -1);
utcs.resize(n*21+1, -1);
for(int i=0; i<n; i++){
string s; cin>>s;
kak.push_back({s.size(),s});
}
sort(kak.rbegin(), kak.rend());
add2(kak[0].second);
for(int i=1; i<n; i++) add(kak[i].second);
dfs(0);
int a=ki.size()-1;
while(ki[a]=='-') a--;
cout<<a+1<<"\n";
for(int i=0; i<=a; i++) cout<<ki[i]<<"\n";
}
