#include <bits/stdc++.h>
using namespace std;
//20.54
bool isbro(string s1, string s2) {
/*兄弟单词:首先长度要一样,其次每个字母出现的频数要一样*/
if (s1 == s2) return false;
if (s1.length() != s2.length()) return false;
vector<char> v(26, 0);
for (int i = 0; i < s1.length(); i++) {
v[s1[i] - 'a']++;
v[s2[i] - 'a']--;
}
for (int i = 0; i < 26; i++) {
if (v[i] != 0) return false;
}
return true;
}
int main() {
int n;
string s;
int k;
while (cin >> n) {
vector<string> v;
vector<string> bro;
while (n--) {
cin >> s;
v.push_back(s);
}
cin >> s; //然后输入一个单词x
cin >> k;
int pos = -1;
//检查是不是兄弟单词
for (int i = 0; i < v.size(); i++) {
if (isbro(v[i], s)) {
bro.push_back(v[i]);
}
}
sort(bro.begin(), bro.end());
cout << bro.size() << endl;
if (k <= bro.size()) {
cout << bro[k - 1];
}
}
}
// 64 位输出请用 printf("%lld")