#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int,int>
#define ll long long
#define vi vector<int>
#define vvi vector<vector<int>>
#define pb push_back
#define all(x) x.begin(), x.end()
#define endl "\n"
#define ff first
#define ss second
#define input(x) for (auto &it : x) cin >> it;
#define output(x) for (auto &it : x) cout << it << ' ';
#define sws std::ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
const int INF = 0x3f3f3f3f3f;
const long double PI = acos(-1);
const int MAX = 1e3 + 5;
const int MOD = 1e9 + 7;
const vector<int> new_node = vector<int>(26, -1);
class Trie
{
public:
vector<vector<int>> adj;
vector<int> max_depth;
vector<bool> str_ends;
Trie()
{
adj.pb(new_node);
str_ends.pb(false);
}
void add_str(string &s)
{
int idx = 0, no = 0;
while (idx < s.size())
{
if (adj[no][s[idx] - 'a'] != -1) no = adj[no][s[idx] - 'a'];
else
{
adj[no][s[idx] - 'a'] = adj.size();
no = adj.size();
adj.pb(new_node);
str_ends.pb(false);
}
idx++;
}
str_ends[no] = true;
}
void process_depth()
{
max_depth = vector<int>(adj.size(), 0);
vector<vector<int>> depth(adj.size(), new_node);
for(int no = adj.size()-1; no >= 0; no--)
{
int mai = 0;
for(int i = 0;i < 26; i++)
{
if (adj[no][i] == -1) depth[no][i] = 0;
else depth[no][i] = 1 + max_depth[adj[no][i]];
mai = max(mai, depth[no][i]);
}
max_depth[no] = mai;
}
}
};
Trie T;
int n;
vector<char> ans;
void dfs(int node)
{
if(T.str_ends[node])
{
ans.pb('P');
}
for(int i = 0; i < 26; i++)
{
if(T.adj[node][i] == -1 || (T.max_depth[T.adj[node][i]] == T.max_depth[node]-1)) continue;
ans.pb('a'+i);
dfs(T.adj[node][i]);
}
for(int i = 0; i < 26; i++)
{
if(T.adj[node][i] == -1)continue;
if(T.max_depth[T.adj[node][i]] != T.max_depth[node]-1) continue;
ans.pb('a'+i);
dfs(T.adj[node][i]);
}
ans.pb('-');
return;
}
void solve()
{
cin >> n;
for(int i = 0; i < n; i++)
{
string s;
cin >> s;
T.add_str(s);
}
T.process_depth();
dfs(0);
int aux = ans.size()-1;
int cnt = aux - T.max_depth[0];
cout << cnt << '\n';
for(int i = 0; i < cnt; i++)cout << ans[i] << '\n';
return;
}
int32_t main()
{ sws
int t;
t = 1;
// cin >> t;
while(t--)
{
solve();
}
return 0;
}
