#include <bits/stdc++.h>

using namespace std;

using ll = long long;

const int mod = 1e9 + 7;

void add(int &x, int y) { if ((x += y - mod) < 0) x += mod; }

const int N = 333;
const int M = 1e3;
const int S = 600;

int n, m;
char str[S + 5];
int len[N + 5], st[N + 5], lenSum, pos[2][S + 5];
struct Trie {
  struct node {
    int ch[26];
    bool end;
  } trie[S + 5];
  int tot = 1;
  void insert(int &u, int c) {
    if (!trie[u].ch[c]) trie[u].ch[c] = ++tot;
    u = trie[u].ch[c];
  }
} trie[2];

int f[M / 2 + 5][S + 5][S + 5], coef, ans;

int main() {
  scanf("%d%d", &n, &m);
  for (int i = 1; i <= n; ++i) {
    st[i] = lenSum, scanf("%s", str + st[i] + 1); lenSum += len[i] = strlen(str + st[i] + 1);
    int u = 1;
    for (int j = 1; j <= len[i]; ++j) trie[0].insert(u, str[st[i] + j] - 'a'), pos[0][st[i] + j] = u;
    trie[0].trie[u].end = 1;
    u = 1;
    for (int j = len[i]; j; --j) trie[1].insert(u, str[st[i] + j] - 'a'), pos[1][st[i] + j] = u;
    trie[1].trie[u].end = 1;
    coef += len[i] == 1;
  }
  if (~m & 1) coef = 1;
  f[0][1][1] = 1;
  for (int l = 0; (l + 1) * 2 <= m; ++l)
    for (int u = 1; u <= trie[0].tot; ++u)
      for (int v = 1; v <= trie[1].tot; ++v)
        if (f[l][u][v]) {
          bool edu = trie[0].trie[u].end, edv = trie[1].trie[v].end;
          for (int c = 0; c < 26; ++c) {
            int du = trie[0].trie[u].ch[c], dv = trie[1].trie[v].ch[c];
            int nu = !edu ? 0 : trie[0].trie[1].ch[c], nv = !edv ? 0 : trie[1].trie[1].ch[c];
            if (du && dv) add(f[l + 1][du][dv], f[l][u][v]);
            if (nu && dv) add(f[l + 1][nu][dv], f[l][u][v]);
            if (du && nv) add(f[l + 1][du][nv], f[l][u][v]);
            if (nu && nv) add(f[l + 1][nu][nv], f[l][u][v]);
          }
        }
  for (int i = 1; i <= n; ++i)
    for (int j = 1; j <= n; ++j)
      ans = (ans + (ll)f[m / 2][pos[0][st[i] + len[i]]][pos[1][st[j] + 1]] * coef) % mod;
  if (m & 1)
    for (int i = 1; i <= n; ++i)
      for (int j = 1; j <= n; ++j) {
        if (len[i] > 1)
          add(ans, f[m / 2][pos[0][st[i] + len[i] - 1]][pos[1][st[j] + 1]]);
        if (len[j] > 1)
          add(ans, f[m / 2][pos[0][st[i] + len[i]]][pos[1][st[j] + 2]]);
      }
  for (int i = 1; i <= n; ++i)
    for (int j = 1; j + (m & 1) < len[i]; ++j)
      add(ans, f[m / 2][j ? pos[0][st[i] + j] : 1][j + 1 + (m & 1) <= len[i] ? pos[1][st[i] + j + 1 + (m & 1)] : 1]);
  printf("%d\n", ans);
}