#include <iostream>
#include <string>
int n;
std::string res = "", maxS = "";
std::string a[100005];
int pos = -1;
int numbPrints = 0;
struct node {
node *child[26];
bool type = false;
int numbWords = 0;
};
node *createNode() {
node *ret = new node();
ret->numbWords = 0;
ret->type = false;
for (int c = 0; c < 26; c++) {
ret->child[c] = NULL;
}
return ret;
}
void addWord(node *root, const std::string &s, bool type) {
node *p = root;
for (int i = 0; i < (int) s.size(); i++) {
if (p->child[s[i] - 'a'] == NULL) {
p->child[s[i] - 'a'] = createNode();
}
p = p->child[s[i] - 'a'];
p->type = type;
}
p->numbWords++;
}
void dfs(node *root) {
for (int i = 1; i <= root->numbWords; i++) {
res += 'P';
numbPrints++;
if (numbPrints == n) {
std::cout << (int) res.size() << std::endl;
for (int i = 0; i < (int) res.size(); i++) {
std::cout << res[i] << std::endl;
}
exit(0);
}
}
char chLast = '.';
for (int c = 0; c < 26; c++) {
if (root->child[c] == NULL) {
continue;
}
if (root->child[c]->type == true) {
chLast = (char) (c + 'a');
break;
}
}
for (int c = 0; c < 26; c++) {
if (root->child[c] == NULL || (char) (c + 'a') == chLast) {
continue;
}
res += (char) (c + 'a');
dfs(root->child[c]);
res += '-';
}
if (chLast != '.') {
res += chLast;
dfs(root->child[chLast - 'a']);
}
}
int main () {
node *root = createNode();
std::cin >> n;
for (int i = 1; i <= n; i++) {
std::string s;
std::cin >> s;
a[i] = s;
if ((int) maxS.size() < (int) s.size()) {
maxS = s;
pos = i;
}
}
for (int i = 1; i <= n; i++) {
if (i != pos) {
addWord(root, a[i], false);
}
}
addWord(root, a[pos], true);
dfs(root);
return 0;
}
