// UUID: 51653dac-a58e-4475-9183-3b03958cec81 #include <bits/stdc++.h> using namespace std; #define int long long vector<char> ans; int word_count = 0; int n; class TrieNode { public: TrieNode* children[26]; bool is_leaf; char c; bool visited; bool longest; TrieNode(char _c) { longest = false; visited = false; c = _c; is_leaf = false; for (int i = 0; i < 26; i++) { children[i] = nullptr; } } }; void insert(TrieNode* root, const string& key, bool longest) { TrieNode* curr = root; for (char c : key) { if (curr->children[c - 'a'] == nullptr) { TrieNode* newNode = new TrieNode(c); curr->children[c - 'a'] = newNode; } curr->longest = longest; curr = curr->children[c - 'a']; } curr->is_leaf = true; } void dfs(TrieNode* curr_node) { if(curr_node->is_leaf) { ans.push_back('P'); word_count++; } if(word_count == n) return; curr_node->visited = true; TrieNode* longest_node = nullptr; for(auto node: curr_node->children) { if(node != nullptr) { if(node->longest) { longest_node = node; continue; } if(!node->visited) { ans.push_back(node->c); dfs(node); if(word_count == n) return; } } } if(longest_node != nullptr && !longest_node->visited) { ans.push_back(longest_node->c); dfs(longest_node); if(word_count == n) return; } if(curr_node->c != ';') ans.push_back('-'); } signed main() { ios::sync_with_stdio(false); cin.tie(0); cin >> n; vector<pair<int, string>> v(n); TrieNode *root = new TrieNode(';'); for(int i = 0; i < n; i++) { cin >> v[i].second; v[i].first = v[i].second.size(); } sort(v.begin(), v.end()); for(int i = 0; i < n-1; i++) insert(root, v[i].second, false); insert(root, v[n-1].second, true); dfs(root); cout << ans.size(); for(char c: ans) cout << "\n" << c; }