#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define is insert
#define MSK(k) (1ULL << k)
#define ton(k, vt) (k|((1ULL) << vt))
#define bat(k, vt) ((k >> vt) & 1)
#define elif else if
#define PROBLEM ""
using namespace std;
/*
/\_/\
(= ._.) ?
/ >0 \>1
*/
// #define and code:
const int maxN = 1e6;
int n;
struct node{
int child[26], cnt;
};
node trie[maxN + 7];
string st, res;
int cnt, ans;
vector<int> g[maxN + 7];
void add(string &it){
int cur = 0;
for(const char &c : it){
int id = c - 'a';
if(!trie[cur].child[id]){
trie[cur].child[id] = ++cnt;
}
cur = trie[cur].child[id];
}
trie[cur].cnt++;
}
int prepare(int u){
vector<pair<int, int>> li;
int hi = 0;
for(int i = 0; i < 26; i++){
if(trie[u].child[i]){
int tmp = prepare(trie[u].child[i]);
li.pb({tmp, i});
hi = max(hi, tmp);
}
}
sort(li.begin(), li.end());
for(const pair<int, int> it : li){
g[u].pb(it.second);
}
return hi + 1;
}
void dfs(int u){
for(int i = 0; i < trie[u].cnt; i++){
res += "P";
ans++;
}
if(ans == n){
cout << res.size() << '\n';
cout << res;
exit(0);
}
for(int v : g[u]){
res += char(v + 'a');
dfs(trie[u].child[v]);
res += "-";
}
}
int main() {
// freopen(PROBLEM".inp", "r", stdin);
// freopen(PROBLEM".out", "w", stdout);
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin >> n;
for(int i = 1; i <= n; i++){
cin >> st;
add(st);
}
prepare(0);
dfs(0);
return 0;
}
