#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <queue>
#include <map>
#include <algorithm>
#include <assert.h>
#define MAXCHAR 26
#define MAXS (1024)
#define MAXNODE 256
#pragma comment( linker, "/STACK:1024000000,1024000000")
using namespace std;
class ACmachine {
public:
struct Node {
Node *next[MAXCHAR], *fail;
int cnt, val, id;
long long dp[30][1024];
int dpable[30][1024];
void init() {
fail = NULL;
cnt = val = 0;
id = 0;
memset(next, 0, sizeof(next));
memset(dp, 0, sizeof(dp));
memset(dpable, 0, sizeof(dp));
}
} nodes[MAXNODE];
Node *root;
int size;
Node* getNode() {
Node *p = &nodes[size++];
p->init();
return p;
}
void init() {
size = 0;
root = getNode();
}
int toIndex(char c) {
return c - 'a';
}
void dfs(Node *p, Node *q) {
for (int i = 0; i < MAXCHAR; i++) {
if (q->next[i]) {
Node *u = p->next[i], *v = q->next[i];
if (u == NULL)
p->next[i] = getNode(), u = p->next[i];
u->cnt |= v->cnt;
dfs(u, v);
}
}
}
void merge(const ACmachine &other) {
dfs(root, other.root);
}
void insert(const char str[], int sid) {
Node *p = root;
for (int i = 0, idx; str[i]; i++) {
idx = toIndex(str[i]);
if (p->next[idx] == NULL)
p->next[idx] = getNode();
p = p->next[idx];
}
p->cnt = 1;
if (sid >= 0) p->id |= 1<<sid;
}
int find(const char str[]) {
Node *p = root;
for (int i = 0, idx; str[i]; i++) {
idx = toIndex(str[i]);
if (p->next[idx] == NULL)
p->next[idx] = getNode();
p = p->next[idx];
}
return p->cnt;
}
void build() {
queue<Node*> Q;
Node *u, *p;
Q.push(root), root->fail = NULL;
while (!Q.empty()) {
u = Q.front(), Q.pop();
for (int i = 0; i < MAXCHAR; i++) {
if (u->next[i] == NULL)
continue;
Q.push(u->next[i]);
p = u->fail;
while (p != NULL && p->next[i] == NULL)
p = p->fail;
if (p == NULL)
u->next[i]->fail = root;
else
u->next[i]->fail = p->next[i];
u->next[i]->val = u->next[i]->fail->val + u->next[i]->cnt;
u->next[i]->id = u->next[i]->fail->id | u->next[i]->id;
}
}
}
int query(const char str[]) {
Node *u = root, *p;
int matched = 0;
for (int i = 0, idx; str[i]; i++) {
idx = toIndex(str[i]);
while (u->next[idx] == NULL && u != root)
u = u->fail;
u = u->next[idx];
u = (u == NULL) ? root : u;
p = u;
matched += p->val;
}
return matched;
}
long long dp(int len, int N) {
queue<Node*> Q;
Node *u, *p;
root->dp[0][0] = 1;
long long ret = 0;
for (int k = 0; k <= len; k++) {
Q.push(root), ret = 0;
while (!Q.empty()) {
u = Q.front(), Q.pop();
ret += u->dp[len][(1<<N)-1];
if (u->dp[len][(1<<N)-1])
u->dpable[len][(1<<N)-1] = 1;
for (int i = 0; i < (1<<N); i++) {
if (i && u->dp[k][i] == 0)
continue;
for (int j = 0; j < MAXCHAR; j++) {
if (u->next[j] != NULL)
if (i == 0) Q.push(u->next[j]);
if (u->dp[k][i] == 0)
continue;
p = u;
while (p != root && p->next[j] == NULL)
p = p->fail;
p = p->next[j];
if (p == NULL) continue;
if (p->id)
p->dp[k+1][i|p->id] += u->dp[k][i];
else
p->dp[k+1][i] += u->dp[k][i];
}
}
}
}
for (int k = len-1; k >= 0; k--) {
Q.push(root);
while (!Q.empty()) {
u = Q.front(), Q.pop();
for (int i = 0; i < (1<<N); i++) {
if (i && u->dp[k][i] == 0)
continue;
for (int j = 0; j < MAXCHAR; j++) {
if (u->next[j] != NULL)
if (i == 0) Q.push(u->next[j]);
if (u->dp[k][i] == 0)
continue;
p = u;
while (p != root && p->next[j] == NULL)
p = p->fail;
p = p->next[j];
if (p == NULL) continue;
if (p->id >= 0) {
if (p->dpable[k+1][i|p->id])
u->dpable[k][i] = 1;
} else {
if (p->dpable[k+1][i])
u->dpable[k][i] = 1;
}
}
}
}
}
return ret;
}
void dpSearch(Node *u, int s, int len, int N, string str, vector<string> &ret) {
if (str.length() == len) {
if (s == (1<<N)-1)
ret.push_back(str);
return ;
}
if (u->dpable[str.length()][s] == 0)
return ;
Node *p;
for (int i = 0; i < MAXCHAR; i++) {
p = u;
while (p != root && p->next[i] == NULL)
p = p->fail;
p = p->next[i];
if (p == NULL) continue;
int ns = s;
if (p->id >= 0)
ns = s|p->id;
dpSearch(p, ns, len, N, str + (char) (i + 'a'), ret);
}
}
void free() {
return ;
queue<Node*> Q;
Q.push(root);
Node *u;
while (!Q.empty()) {
u = Q.front(), Q.pop();
for (int i = 0; i < MAXCHAR; i++) {
if (u->next[i] != NULL) {
Q.push(u->next[i]);
}
}
delete u;
}
}
};
ACmachine g;
int main() {
int M, N, cases = 0;
char s[1024];
while (scanf("%d %d", &M, &N) == 2 && M+N) {
g.init();
for (int i = 0; i < N; i++) {
scanf("%s", s);
g.insert(s, i);
}
for (int i = 'a'; i <= 'z'; i++) {
s[0] = i, s[1] = '\0';
g.insert(s, -1);
}
g.build();
long long way = g.dp(M, N);
printf("Case %d: %lld suspects\n", ++cases, way);
if (way <= 42) {
vector<string> pwd;
g.dpSearch(g.root, 0, M, N, "", pwd);
sort(pwd.begin(), pwd.end());
for (int i = 0; i < pwd.size(); i++)
printf("%s\n", pwd[i].c_str());
}
g.free();
}
return 0;
}
