#include <iostream> //cin, cout
// #include <fstream>
// std::ifstream cin ("slingshot.in");
// std::ofstream cout ("slingshot.out");
// includes
#include <cmath>
#include <set>
#include <map>
#include <queue>
#include <string>
#include <vector>
#include <array>
#include <algorithm>
#include <numeric>
#include <iomanip>
#include <unordered_set>
#include <stack>
#include <ext/pb_ds/assoc_container.hpp>
#include <random>
#include <chrono>
#include <bitset>
#include <complex>
//usings
using namespace std;
using namespace __gnu_pbds;
// misc
#define ll long long
#define ld long double
#define pb push_back
#define pq priority_queue
#define ub upper_bound
#define lb lower_bound
template<typename T, typename U> bool emin(T &a, const U &b){ return b < a ? a = b, true : false; }
template<typename T, typename U> bool emax(T &a, const U &b){ return b > a ? a = b, true : false; }
typedef uint64_t hash_t;
// vectors
#define vi vector<int>
#define vvi vector<vi>
#define vvvi vector<vvi>
#define vpii vector<pair<int, int>>
#define vvpii vector<vector<pair<int, int>>>
#define vppipi vector<pair<int, pair<int, int>>>
#define vl vector<ll>
#define vvl vector<vl>
#define vvvl vector<vvl>
#define vpll vector<pair<ll, ll>>
#define vvpll vector<vpll>
#define vb vector<bool>
#define vvb vector<vb>
#define vs vector<string>
#define sz(x) (int)x.size()
#define rz resize
#define all(x) x.begin(), x.end()
#define vc vector<char>
#define vvc vector<vc>
// pairs
#define pii pair<int, int>
#define pll pair<ll, ll>
#define mp make_pair
#define f first
#define s second
// sets
#define si set<int>
#define sl set<ll>
#define ss set<string>
#define in insert
template <class T> using iset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
// maps
#define mii map<int, int>
#define mll map<ll, ll>
// loops
#define FR(x, z, y) for (int x = z; x < y; x++)
#define FRE(x, z, y) FR(x, z, y + 1)
#define F(x, y) FR(x, 0, y)
#define FE(x, y) F(x, y + 1)
#define A(x, y) for(auto &x : y)
int n;
int ct = 1;
vector<char> ans;
struct node {
vi c; bool word;
int d; char w;
node(){
c = vi(26, -1);
word = false;
d = 0;
w = '.';
}
};
vector<node> a(1);
void in(int x, string z){
F(i, sz(z)){
emax(a[x].d, sz(z));
if(a[x].c[z[i] - 'a'] == -1) {
node temp = node();
temp.w = z[i];
a[x].c[z[i] - 'a'] = ct++, a.pb(temp);
}
x = a[x].c[z[i] - 'a'];
}
emax(a[x].d, sz(z));
a[x].word = true;
}
void get(int x){
if(a[x].word) ans.pb('P');
F(i, 26) {
if(a[x].c[i] != -1 && a[a[x].c[i]].d < a[x].d) {
ans.pb(a[a[x].c[i]].w);
get(a[x].c[i]);
ans.pb('-');
}
}
F(i, 26) {
if(a[x].c[i] != -1 && a[a[x].c[i]].d == a[x].d) {
ans.pb(a[a[x].c[i]].w);
get(a[x].c[i]);
ans.pb('-');
}
}
}
int main(){
cin >> n;
F(i, n) {string z; cin >> z; in(0, z);}
get(0);
while(sz(ans) > 0 && ans.back() != 'P') ans.pop_back();
cout << sz(ans);
A(u, ans) cout << u << endl;
}
