#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")

////////////////////////////////////////////////////////////////////////////////
template <unsigned M_> struct ModInt {
  static constexpr unsigned M = M_;
  unsigned x;
  constexpr ModInt() : x(0U) {}
  constexpr ModInt(unsigned x_) : x(x_ % M) {}
  constexpr ModInt(unsigned long long x_) : x(x_ % M) {}
  constexpr ModInt(int x_) : x(((x_ %= static_cast<int>(M)) < 0) ? (x_ + static_cast<int>(M)) : x_) {}
  constexpr ModInt(long long x_) : x(((x_ %= static_cast<long long>(M)) < 0) ? (x_ + static_cast<long long>(M)) : x_) {}
  ModInt &operator+=(const ModInt &a) { x = ((x += a.x) >= M) ? (x - M) : x; return *this; }
  ModInt &operator-=(const ModInt &a) { x = ((x -= a.x) >= M) ? (x + M) : x; return *this; }
  ModInt &operator*=(const ModInt &a) { x = (static_cast<unsigned long long>(x) * a.x) % M; return *this; }
  ModInt &operator/=(const ModInt &a) { return (*this *= a.inv()); }
  ModInt pow(long long e) const {
    if (e < 0) return inv().pow(-e);
    ModInt a = *this, b = 1U; for (; e; e >>= 1) { if (e & 1) b *= a; a *= a; } return b;
  }
  ModInt inv() const {
    unsigned a = M, b = x; int y = 0, z = 1;
    for (; b; ) { const unsigned q = a / b; const unsigned c = a - q * b; a = b; b = c; const int w = y - static_cast<int>(q) * z; y = z; z = w; }
    assert(a == 1U); return ModInt(y);
  }
  ModInt operator+() const { return *this; }
  ModInt operator-() const { ModInt a; a.x = x ? (M - x) : 0U; return a; }
  ModInt operator+(const ModInt &a) const { return (ModInt(*this) += a); }
  ModInt operator-(const ModInt &a) const { return (ModInt(*this) -= a); }
  ModInt operator*(const ModInt &a) const { return (ModInt(*this) *= a); }
  ModInt operator/(const ModInt &a) const { return (ModInt(*this) /= a); }
  template <class T> friend ModInt operator+(T a, const ModInt &b) { return (ModInt(a) += b); }
  template <class T> friend ModInt operator-(T a, const ModInt &b) { return (ModInt(a) -= b); }
  template <class T> friend ModInt operator*(T a, const ModInt &b) { return (ModInt(a) *= b); }
  template <class T> friend ModInt operator/(T a, const ModInt &b) { return (ModInt(a) /= b); }
  explicit operator bool() const { return x; }
  bool operator==(const ModInt &a) const { return (x == a.x); }
  bool operator!=(const ModInt &a) const { return (x != a.x); }
  friend std::ostream &operator<<(std::ostream &os, const ModInt &a) { return os << a.x; }
};
////////////////////////////////////////////////////////////////////////////////

constexpr unsigned MO = 1000000007;
using Mint = ModInt<MO>;


constexpr int A = 26;

int N, K;
char S[10'010][20], T[10'010][20];

int main() {
  for (; ~scanf("%d%d", &N, &K); ) {
    for (int n = 0; n < N; ++n) {
      scanf("%s", S[n]);
      scanf("%s", T[n]);
    }
    
    vector<int> can(K, (1 << A) - 1);
    for (int n = 0; n < N; ++n) {
      for (int k = 0; k < K; ++k) {
        const int a = S[n][k] - 'A';
        can[k] &= (T[n][k] == 'O') ? (1 << a) : ~(1 << a);
      }
    }
    
    bool ok = true;
    vector<int> L(A, 0), R(A, N);
    for (int n = 0; n < N; ++n) {
      vector<string> ts(A);
      for (int k = 0; k < K; ++k) if (T[n][k] == 'O') {
        const int a = S[n][k] - 'A';
        ts[a] += '-';
      }
      for (int k = 0; k < K; ++k) if (T[n][k] != 'O') {
        const int a = S[n][k] - 'A';
        ts[a] += T[n][k];
      }
      for (int a = 0; a < A; ++a) {
        const int len = ts[a].size();
        const int l = count(ts[a].begin(), ts[a].end(), '-');
        ok = ok && (ts[a] == string(l, '-') + string(len - l, 'x'));
        chmax(L[a], l);
        if (l < len) chmin(R[a], l);
      }
    }
    for (int a = 0; a < A; ++a) {
      ok = ok && (L[a] <= R[a]);
    }
    vector<int> as;
    for (int a = 0; a < A; ++a) for (int i = 0; i < L[a]; ++i) as.push_back(a);
    const int asLen = as.size();
    ok = ok && ((int)asLen <= K);
    
    Mint ans = 0;
    if (ok) {
cerr<<"L = "<<L<<endl;
cerr<<"R = "<<R<<endl;
cerr<<"as = "<<as<<endl;
      int amari = 0;
      for (int a = 0; a < A; ++a) if (L[a] < R[a]) amari |= 1 << a;
      vector<Mint> dp(1 << K, 0);
      dp[0] = 1;
      for (int p = 0; p < (1 << K) - 1; ++p) if (dp[p]) {
        const int k = __builtin_popcount(p);
        for (int i = 0; i < asLen; ++i) if (!(p & 1 << i)) {
          if (i - 1 >= 0 && as[i - 1] == as[i] && !(p & 1 << (i - 1))) continue;
          if (can[k] & 1 << as[i]) {
            dp[p | 1 << i] += dp[p];
          }
        }
        int ama = amari;
        for (int i = 0; i < asLen; ++i) if (!(p & 1 << i)) ama &= ~(1 << as[i]);
        for (int i = asLen; i < K; ++i) if (!(p & 1 << i)) {
          dp[p | 1 << i] += dp[p] * __builtin_popcount(can[k] & ama);
          break;
        }
      }
      ans = dp.back();
    }
    printf("%u\n", ans.x);
  }
  return 0;
}