1 /* http://www.cnblogs.com/karl07/ */
 2 #include<cstdlib>
 3 #include<cstdio>
 4 #include<cstring>
 5 #include<cmath>
 6 #include<algorithm>
 7 using namespace std;
 8 
 9 #define P 10007
10 struct trie{
11     trie *next[26],*fail;
12     int th,w;
13 }t[6005],*root=t,*NEW=t,*q[6005];
14 
15 int n,m,l,r,ans;
16 int f[105][6005];
17 char s[105];
18 
19 trie *new1(){NEW++; NEW->th=NEW->w=0; return NEW;}
20 
21 #define pnf p->next[i]->fail
22 #define pn p->next[i]
23 trie *insert(trie *p,int i,int w){
24     if (!pn) pn=new1();
25     pn->w|=w;
26     return pn;
27 }
28 
29 void build_fail(){
30     trie *p=q[0]=root;
31     for (int i=0;i<26;i++) if (pn) pnf=p,q[++r]=pn,pn->th=r;
32     while (l<r){
33         p=q[++l];
34         for (int i=0;i<26;i++){
35             if (pn){
36                 q[++r]=pn,pn->th=r;
37                 for (pnf=p->fail ; pnf!=root && !pnf->next[i] ; pnf=pnf->fail);
38                 if (pnf->next[i]) pnf=pnf->next[i];
39                 pn->w|=pnf->w;
40             }
41         }
42     }
43 }
44 
45 int Q_pow(int x,int y){
46     int ans=1;
47     for (;y; x=x*x%P , y=y>>1 ) if (y&1) ans=ans*x%P;
48     return ans;
49 }
50 void dp(){
51     f[0][0]=1;
52     for (int k=0;k<m;k++){
53         for (int j=0;j<=r;j++) if (f[k][j] && !q[j]->w){
54             for (int i=0;i<26;i++){
55                 trie *p=q[j];
56                 while (!pn && p!=root) p=p->fail;
57                 if (pn) p=pn;
58                 f[k+1][p->th]=(f[k+1][p->th]+f[k][j])%P;
59             }
60         }
61     }
62     for (int i=0;i<=r;i++) if (!q[i]->w) ans=(ans+f[m][i])%P;
63     printf("%d\n",(Q_pow(26,m)-ans+P)%P);
64 }
65 #undef pn
66 #undef pnf
67 
68 int main(){
69     scanf("%d%d",&n,&m);
70     for (int i=1;i<=n;i++){
71         scanf("%s",s);
72         int j=0,l=strlen(s);
73         for (trie *p=root;j<l;j++) p=insert(p,s[j]-‘A‘,j==l-1);
74     }
75     build_fail();
76     dp();
77     return 0;
78 }