// #define OJ
// #define TEST
#include <bits/stdc++.h>
using namespace std;
#ifdef OJ
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#endif
#ifndef ALY
#define ALY
static int __star = []{
ios_base::sync_with_stdio(0);
cin.tie(NULL),cout.tie(NULL);
return 0;
}();
using ll = long long;
using ull = unsigned long long;
using uint = unsigned int;
using u8 = uint8_t;
using u16 = uint16_t;
using u32 = uint32_t;
using u64 = uint64_t;
using in8 = uint8_t;
using in16 = uint16_t;
using in32 = uint32_t;
using in64 = uint64_t;
using db = long double;
using str = string;
using pi = pair<int,int>;
using pl = pair<ll,ll>;
#define mp make_pair
#define f first
#define s second
#define vcA template<class A
vcA> using V = vector<A>;
vcA> using MAT = V<V<A>>;
using vi = V<int>;
using vb = V<bool>;
using vl = V<ll>;
using vd = V<db>;
using vs = V<str>;
using vpi = V<pi>;
using vpl = V<pl>;
using mat = V<vi>;
using matl = V<vl>;
#define sz(x) int((x).size())
#define bg(x) begin(x)
#define rbg(x) rbegin(x)
#define ed(x) end(x)
#define all(x) begin(x), end(x)
#define pfr(x, a) begin(x), begin(x) + a
#define rall(x) x.rbegin(), x.rend()
#define srt(x) sort(all(x))
#define nth(x, a) nth_element(pfr(x, a), ed(x))
#define npp(x) next_permutation(all(x))
#define shl(x, a) ((x) << (a))
#define shr(x, a) ((x) >> (a))
#define pb push_back
#define pf push_front
#define eb emplace_back
#define em empty()
#define ft front()
#define bk back()
#define ppb pop_back()
#define ppf pop_front()
#define pp pop()
#define tp top()
#define lb lower_bound
#define ub upper_bound
#define FOR(i, a, b) for(int i = (a); i < (b); ++i)
#define F0R(i, a) FOR(i, 0, a)
#define ROF(i, a, b) for(int i = (b) - 1; i >= (a); --i)
#define R0F(i, a) ROF(i, 0, a)
#define xtime(a) F0R(_, a)
#define each(a, x) for(auto& a : x)
static constexpr int MOD = 1'000'000'007;
static constexpr int MD2 = 1'000'000'009;
static constexpr int ALT = 998'244'353;
static constexpr u64 B1 = 911'382'323;
static constexpr u64 B2 = 972'663'749;
static constexpr ll LMX = 1e18;
static constexpr int XDIR[4] {1, 0, -1, 0}, YDIR[4] {0, 1, 0, -1};
template<class P> using pqpl = priority_queue<P, vector<P>, greater<P>>;
template<class P> using pqpg = priority_queue<P, vector<P>, less<P>>;
constexpr int pct(int x) { return __builtin_popcount(x); }
constexpr int ctz(int x) { return __builtin_ctz(x); }
constexpr int clz(int x) { return __builtin_clz(x); }
constexpr int pctll(ll x) { return __builtin_popcountll(x); }
constexpr int ctzll(ll x) { return __builtin_ctzll(x); }
constexpr int clzll(ll x) { return __builtin_clzll(x); }
ll ceill(ll a, ll b) { return (a + b - 1) / b; }
vcA> void printvec(V<A>&a) { each(v,a) { cout << v << ' '; } cout << '\n'; }
// binstr
template<typename C>
void meow(C num) { for(int bits = sizeof(num) * 8; bits--; num >>= 1) cout << !!(num & 1); cout << '\n'; }
// pos of msb, msb(0) = -1, msb(2) = 1, msb(1) = 0, etc.
template<typename C>
int woof(C n) {
if(!n) return -1;
switch(sizeof(C)) {
case 1: return 7 - clz(static_cast<uint>(n) << 24);
case 2: return 15 - clz(static_cast<uint>(n) << 16);
case 4: return 31 - clz(static_cast<uint>(n));
case 8: return 63 - clzll(static_cast<ull>(n));
}
return -1;
}
// for coordinate comp
template<typename T>
int v2i(V<T>& A, T val) { return int(lower_bound(all(A), val) - bg(A)); }
#endif
struct node {
int depth = 0, word = 0;
node* nxt[26]{nullptr};
};
struct trie {
node* root;
trie(vs& A) : root(new node) {
each(i, A) ins(i);
pull(root, 0);
};
void ins(str& s) {
node* cur = root;
each(c, s) {
auto& nxt = cur->nxt[c - 'a'];
if(!nxt) nxt = new node;
cur = nxt;
}
cur->word = 1;
}
int pull(node* cur, int d) {
int ret = d;
F0R(i, 26) if(cur->nxt[i])
ret = max(ret, pull(cur->nxt[i], d + 1));
return cur->depth = ret;
}
void dfs(node* cur, str& s) {
if(cur->word) s.pb('P');
F0R(i, 26) if(cur->nxt[i]) {
s.pb(char('a' + i));
dfs(cur->nxt[i], s);
s.pb('-');
}
}
void solve(node* cur, str& s) {
if(cur->word) s.pb('P');
int nxt = -1;
F0R(i, 26) if(cur->nxt[i]) {
if(cur->nxt[i]->depth == cur->depth && nxt == -1) {
nxt = i;
continue;
}
s.pb(char('a' + i));
dfs(cur->nxt[i], s);
s.pb('-');
}
if(nxt == -1) return;
s.pb(char('a' + nxt));
solve(cur->nxt[nxt], s);
}
void solve() {
str s;
solve(root, s);
cout << sz(s) << '\n';
each(c, s) cout << c << '\n';
}
};
int main() {
#ifdef TEST
#else
int n; cin >> n;
vs A(n); each(i, A) cin >> i;
trie T(A);
T.solve();
#endif
return 0;
}
