#include <bits/stdc++.h>
using namespace std;
#ifndef ONLINE_JUDGE
#include "debug.h"
#else
#define debug(...) 417
#endif
using i64 = int64_t;
constexpr i64 mod = 1000000007;
void add(i64& x, i64 y) {
  if ((x += y) >= mod) { x -= mod; }
}
int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  cout << fixed << setprecision(20);
  int n, l;
  cin >> n >> l;
  vector<string> s(n);
  string ss;
  vector<int> begin(n);
  for (int i = 0; i < n; i += 1) {
    cin >> s[i];
    begin[i] = ss.size();
    ss += s[i];
  }
  debug(s);
  int m = ss.size();
  vector<int> id(m, -1);
  for (int i = 0; i < n; i += 1) { id[begin[i]] = i; }
  for (int j = 0; j < m; j += 1) {
    if (id[j] == -1) { id[j] = id[j - 1]; }
  }
  vector<vector<int>> p((m + 1) * (m + 1));
  for (int i = 0; i <= m; i += 1) {
    for (int j = 0; j <= m; j += 1) {
      if (i == m and j == m) {
        for (int si = 0; si < n; si += 1) {
          for (int sj = 0; sj < n; sj += 1) {
            if (s[si][0] == s[sj].back()) {
              int x = s[si].size() == 1 ? m : begin[si];
              int y = s[sj].size() == 1 ? m : begin[sj] + ssize(s[sj]) - 1;
              p[i * (m + 1) + j].push_back(x * (m + 1) + y);
            }
          }
        }
        continue;
      }
      if (i == m) {
        int sj = id[j];
        for (int si = 0; si < n; si += 1) {
          if (s[si][0] == s[sj][j - begin[sj] - 1]) {
            int x = s[si].size() == 1 ? m : begin[si];
            int y = j - id[j] - 1 == 0 ? m : j - 1;
            p[i * (m + 1) + j].push_back(x * (m + 1) + y);
          }
        }
        continue;
      }
      if (j == m) {
        int si = id[i];
        for (int sj = 0; sj < n; sj += 1) {
          if (s[si][i - begin[si] + 1] == s[sj].back()) {
            int x = i - begin[si] + 1 == ssize(s[si]) - 1 ? m : i + 1;
            int y = s[sj].size() == 1 ? m : begin[sj] + ssize(s[sj]) - 1;
            p[i * (m + 1) + j].push_back(x * (m + 1) + y);
          }
        }
        continue;
      }
      int si = id[i];
      int sj = id[j];
      if (s[si][i - begin[si] + 1] == s[sj][j - begin[sj] - 1]) {
        int x = i - begin[si] + 1 == ssize(s[si]) - 1 ? m : i + 1;
        int y = j - begin[sj] - 1 == 0 ? m : j - 1;
        p[i * (m + 1) + j].push_back(x * (m + 1) + y);
      }
    }
  }
  vector<i64> f((m + 1) * (m + 1));
  if (l % 2) {
    for (int i = 0; i < n; i += 1) {
      for (int j = 0; j < ssize(s[i]); j += 1) {
        int x = j == ssize(s[i]) - 1 ? m : begin[i] + j;
        int y = j == 0 ? m : begin[i] + j;
        f[x * (m + 1) + y] += 1;
      }
    }
  } else {
    for (int i = 0; i < n; i += 1) {
      for (int j = 0; j < n; j += 1) {
        if (s[i][0] == s[j].back()) {
          int x = s[i].size() == 1 ? m : begin[i];
          int y = s[j].size() == 1 ? m : begin[j] + ssize(s[j]) - 1;
          f[x * (m + 1) + y] += 1;
        }
      }
    }
    for (int i = 0; i < n; i += 1) {
      for (int j = 0; j + 1 < ssize(s[i]); j += 1) {
        if (s[i][j] == s[i][j + 1]) {
          int x = j + 1 == ssize(s[i]) - 1 ? m : begin[i] + j + 1;
          int y = j == 0 ? m : begin[j];
          f[x * (m + 1) + y] += 1;
        }
      }
    }
  }
  debug(begin);
  debug(f);
  debug(p);
  for (int i = 0; i < (l - 1) / 2; i += 1) {
    vector<i64> g((m + 1) * (m + 1));
    for (int i = 0; i < (m + 1) * (m + 1); i += 1) {
      if (f[i]) {
        for (int j : p[i]) { add(g[j], f[i]); }
      }
    }
    f.swap(g);
  }
  cout << f.back();
}