#include<iostream>

 #include<cstring>

 #include<cstdio>

 #include<cmath>

 #include<algorithm>

 using namespace std;

 #define MOD 1000000007

 int dp[][][][];

 int trie[][];

 int o[];

 int fail[],que[],p[][];

 int t;

 void CL()

 {

     t = ;

     memset(trie,-,sizeof(trie));

     memset(o,,sizeof(o));

     memset(p,,sizeof(p));

 }

 void insert(char *s,int x)

 {

     int i,root,len,temp;

     len = strlen(s);

     root = ;

     for(i = ; i < len; i ++)

     {

         temp = s[i] == 'D' ? :;

         if(trie[root][temp] == -)

             trie[root][temp] = t ++;

         root = trie[root][temp];

     }

     o[root] = <<x;

 }

 void build_ac()

 {

     int head,tail,front,i;

     head = tail = ;

     for(i = ; i < ; i ++)

     {

         if(trie[][i] != -)

         {

             fail[trie[][i]] = ;

             que[tail++] = trie[][i];

         }

         else

             trie[][i] = ;

     }

     while(head != tail)

     {

         front = que[head++];

         o[front] |= o[fail[front]];

         for(i = ; i < ; i ++)

         {

             if(trie[front][i] != -)

             {

                 que[tail++] = trie[front][i];

                 fail[trie[front][i]] = trie[fail[front]][i];

             }

             else

             {

                 trie[front][i] = trie[fail[front]][i];

             }

         }

     }

 }

 int main()

 {

     int cas,i,j,k,u,n,m,temp;

     char str[];

     scanf("%d",&cas);

     while(cas--)

     {

         CL();

         scanf("%d%d",&n,&m);

         for(i = ; i < ; i ++)

         {

             scanf("%s",str);

             insert(str,i);

         }

         for(i = ; i <= n; i ++)

         {

             for(j = ; j <= m; j ++)

             {

                 for(k = ; k < t; k ++)

                 {

                     for(u = ; u < ; u ++)

                         dp[i][j][k][u] = ;

                 }

             }

         }

         build_ac();

         dp[][][][] = ;

         for(i = ; i <= n; i ++)

         {

             for(j = ; j <= m; j ++)

             {

                 for(k = ; k < t; k ++)

                 {

                     for(u = ; u < ; u ++)

                     {

                         if(i != n)

                         {

                             temp = trie[k][];

                             dp[i+][j][temp][u|o[temp]] = (dp[i+][j][temp][u|o[temp]] + dp[i][j][k][u])%MOD;

                         }

                         if(j != m)

                         {

                             temp = trie[k][];

                             dp[i][j+][temp][u|o[temp]] = (dp[i][j+][temp][u|o[temp]] + dp[i][j][k][u])%MOD;

                         }

                     }

                 }

             }

         }

         int ans = ;

         for(i = ; i < t; i ++)

         {

             ans = (ans + dp[n][m][i][])%MOD;

         }

         printf("%d\n",ans);

     }

     return ;

 }