#include <bits/stdc++.h>
#define _for(i, a, b) for (int i = (a); i < (int)(b); ++i)
using namespace std;
const int SIG = 26, NN = 25004;
struct Trie {
struct Node {
int ch[SIG], mark, end;
} T[NN * 20];
int sz = 0;
void insert(const string& s) {
int u = 0;
for (char c : s) {
int d = c - 'a', &cu = T[u].ch[d];
if (!cu) cu = ++sz;
u = cu;
}
T[u].end = true;
}
void dfs(int u, string& ans) {
const Node& x = T[u];
if (x.end) ans += 'P';
int mi = -1;
for (int i = 0; i < SIG; ++i) {
int v = x.ch[i];
if (!v) continue;
if (T[v].mark) mi = i;
else ans += i + 'a', dfs(v, ans);
}
if (mi != -1) ans += mi + 'a', dfs(x.ch[mi], ans);
ans += '-';
}
} Tr;
int main(void) {
ios::sync_with_stdio(false), cin.tie(0);
int n; cin >> n;
string s, l;
_for(i, 0, n) {
cin >> s, Tr.insert(s);
if (s.length() > l.length()) l = s;
}
int u = 0;
_for(i, 0, l.size())
u = Tr.T[u].ch[l[i] - 'a'], Tr.T[u].mark = true;
s.clear(), Tr.dfs(0, s);
while (s.back() == '-') s.pop_back();
cout << s.size() << "\n";
for (char c : s) cout << c << "\n";
return 0;
}
