// UUID: 9c9dc833-6750-4697-80c8-cd36b4f8b743
#include <bits/stdc++.h>
using ll = long long;
using namespace std;
vector<vector<int>> t;
vector<char> csak_ide_ne;
vector<bool> veg;
string ans;
int cnt = 0;
void add(string s, bool spec) {
int cur = 0;
for (char c : s) {
if (!t[cur][c-'a']) {
cnt++;
t[cur][c-'a'] = cnt;
}
if (spec) csak_ide_ne[cur] = c-'a';
cur = t[cur][c-'a'];
}
veg[cur] = true;
}
void dfs(int cur) {
cerr << cur << "\n";
if (veg[cur]) ans += 'P';
for (int i = 0; i < 26; i++) {
if (csak_ide_ne[cur] == i || t[cur][i] == 0) continue;
ans += i+'a';
dfs(t[cur][i]);
ans += '-';
}
int i = csak_ide_ne[cur];
if (t[cur][i]) {
ans += i+'a';
dfs(t[cur][i]);
ans += '-';
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
int n; cin >> n;
vector<string> s(n);
csak_ide_ne.assign(n*23, 0);
t.assign(n*23, vector<int>(26));
veg.resize(n*23, 0);
int lg = 0;
for (int i = 0; i < n; i++) {
cin >> s[i];
lg = max((int) s[i].size(), lg);
}
string y;
for (string x : s) {
if ((int) x.size() == lg) {
y = x;
continue;
}
add(x, false);
}
add(y, true);
dfs(0);
while (ans.back() == '-') ans.pop_back();
cout << ans.size() << "\n";
for (char c : ans) cout << c << "\n";
return 0;
}
