#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <iomanip>
#include <set>
#include <map>
#include <numeric>
#include <iomanip>
#include <unordered_set>
#include <unordered_map>
#include <bitset>
#include <queue>
#include <deque>
#include <stack>
#include <cmath>
#include <tuple>
#include <cassert>
#include <array>
#include <list>
#include <random>
#include <initializer_list>
#include <chrono>
using namespace std;
using i64 = long long;
using u64 = unsigned long long;
constexpr i64 N = 3E5 + 10;
i64 trie[N][26], f[N], d[N];
i64 tot;
i64 newNode() {
i64 x = ++tot;
for (i64 i = 0; i < 26; i++) {
trie[x][i] = 0;
}
f[x] = d[x] = 0;
return x;
};
void init() {
tot = 0;
newNode();
}
void add(string s) {
i64 o = 1;
for (i64 i = 0; i < s.size(); i++) {
i64& p = trie[o][s[i] - 'a'];
if (!p) {
p = newNode();
}
o = p;
}
f[o] = 1;
}
void solve() {
init();
i64 n;
cin >> n;
for (i64 i = 0; i < n; i++) {
string s;
cin >> s;
add(s);
}
auto work = [&](auto& self, i64 x) -> void {
for (i64 i = 0; i < 26; i++) {
if (trie[x][i]) {
self(self, trie[x][i]);
d[x] = max(d[x], d[trie[x][i]] + 1);
}
}
};
work(work, 1);
vector<char> ans;
auto dfs = [&](auto& self, i64 x) -> void {
if (f[x]) {
ans.push_back('P');
}
vector<i64> id(26);
iota(id.begin(), id.end(), 0);
sort(id.begin(), id.end(), [&](i64 i, i64 j) {
return d[trie[x][i]] < d[trie[x][j]];
});
for (auto i: id) {
if (!trie[x][i]) {
continue;
}
ans.push_back('a' + i);
self(self, trie[x][i]);
ans.push_back('-');
}
};
dfs(dfs, 1);
while (ans.back() == '-') {
ans.pop_back();
}
cout << ans.size() << '\n';
for (auto x : ans) {
cout << char(x) << '\n';
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int t = 1;
//cin >> t;
while (t--) {
solve();
}
}
