#include <bits/stdc++.h>
#define int long long
using namespace std;
struct node{
node *adj[26];
int dep, maxdep, newend;
node()
{
for(int i = 0; i < 26; i++)
{
adj[i]=0;
} maxdep=dep=0;
}
};
node *root = new node;
void insert(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->newend++;
}
void dfs1(node *cur)
{
cur -> maxdep = cur -> dep;
for(int i = 0; i < 26; i++)
{
if(cur -> adj[i])
{
cur->adj[i]->dep = cur->dep+1;
dfs1(cur->adj[i]);
cur->maxdep = max(cur->maxdep, cur->adj[i]->maxdep);
}
}
}
string ans;
void dfs2(node *cur)
{
while(cur->newend--) ans+='P';
int m = -1;
for(int i =0 ; i < 26; i++)
{
if(cur->adj[i])
{
if(m==-1 || cur->adj[m]->maxdep < cur->adj[i]->maxdep) m = i;
}
}
for(int i = 0; i < 26; i++)
{
if(cur->adj[i]&&i!=m)
{
ans+=i+'a';
dfs2(cur->adj[i]);
ans+='-';
}
}
if(m!=-1)
{
ans+=m+'a';
dfs2(cur->adj[m]);
ans+='-';
}
}
signed main()
{
cin.tie(0)->sync_with_stdio(0);
int n; cin>>n;
for(int i = 0; i < n; i++) {
string s; cin>>s; insert(s);
}
dfs1(root);
dfs2(root);
while(ans.back()=='-') ans.pop_back();
cout<<ans.size()<<"\n";
for(auto c : ans) cout<<c<<"\n";
return 0;
}
