#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
#define TASK "task"
#define all(x) x.begin(), x.end()
const int N = 2e5 + 7;
const int MOD = 1e9 + 7;
const int INF = 1e9 + 7;
const long long INFLL = 1e18 + 7;
using namespace std;
template <class X, class Y> bool minimize(X &a, Y b) {
if (a > b) return a = b, true;
return false;
}
template <class X, class Y> bool maximize(X &a, Y b) {
if (a < b) return a = b, true;
return false;
}
struct Node {
Node *child[26];
bool exist;
int max_dist;
Node() {
for (int i = 0; i < 26; i ++)
child[i] = nullptr;
max_dist = 0;
}
};
Node *root = new Node();
void dfs(Node *cur) {
for (int c = 0; c < 26; c ++) {
if (cur->child[c] == nullptr)
continue;
dfs(cur->child[c]);
maximize(cur->max_dist, cur->child[c]->max_dist + 1);
}
}
vector<char> oper;
void print(Node *cur, bool longest) {
if (cur->exist) {
oper.push_back('P');
}
bool ok = true;
for (int c = 0; c < 26; c ++) {
if (cur->child[c] == nullptr)
continue;
bool n_longest = longest & (cur->max_dist == cur->child[c]->max_dist + 1);
if (!(n_longest & ok)) {
oper.push_back(char (c + 'a'));
print(cur->child[c], n_longest & ok);
}
if (n_longest) ok = false;
}
for (int c = 0; c < 26; c ++) {
if (cur->child[c] == nullptr)
continue;
bool n_longest = longest & (cur->max_dist == cur->child[c]->max_dist + 1);
if (n_longest) {
oper.push_back(char (c + 'a'));
print(cur->child[c], n_longest);
break;
}
}
if (!longest) oper.push_back('-');
}
void solve(void) {
auto add = [&](string s) {
Node *p = root;
for (int i = 0; i < (int) s.size(); i ++) {
int c = s[i] - 'a';
if (p->child[c] == nullptr) p->child[c] = new Node();
p = p->child[c];
}
p->exist = true;
};
int n; cin >> n;
for (int i = 1; i <= n; i ++) {
string s; cin >> s;
add(s);
}
dfs(root);
print(root, true);
cout << oper.size() << '\n';
for (char x: oper) cout << x << '\n';
}
signed main(void) {
cin.tie(0)->sync_with_stdio(0);
int test = 1;
// cin >> test;
while (test --) {
solve();
}
return 0;
}
