#include <bits/stdc++.h>

using namespace std;

const int N = 20, MOD = 1e9 + 7;
inline int Plus(int a, int b) {return a + b >= MOD ? a + b - MOD : a + b; }
inline int Minus(int a, int b) {return a - b < 0 ? a - b + MOD : a - b; }
inline int ksm(long long a, int b) {
    long long r = 1;
    for(; b; b >>= 1, a = a * a % MOD)
        if(b & 1) r = r * a % MOD;
    return r;
}
int n, ban[N], L[26], R[26];
int f[N][1 << N];

inline int solve() {
    int T; cin >> T >> n;
    for(int i = 0; i < 26; i ++) L[i] = 0, R[i] = n;
    while(T --) {
        string A, B; cin >> A >> B;
        vector<int> siz(26, 0);
        for(int i = 0; i < n; i ++) if(B[i] == 'O') {
            siz[A[i] - 'A'] ++;
            ban[i] |= ((1 << 26) - 1) ^ (1 << A[i] - 'A');
        } 
        for(int i = 0; i < n; i ++) if(B[i] != 'O') {
            if(B[i] == '-') L[A[i] - 'A'] = max(L[A[i] - 'A'], ++siz[A[i] - 'A']);
            else R[A[i] - 'A'] = min(R[A[i] - 'A'], siz[A[i] - 'A']);
            ban[i] |= 1 << (A[i] - 'A');
        }
        for(int i = 0; i < 26; i ++) L[i] = max(L[i], siz[i]);
    }
    for(int i = 0; i < 26; i ++)
        if(L[i] > R[i]) return 0;
    
    int least = 0;
    for(int i = 0; i < 26; i ++)
        least += L[i];
    if(least > n) return 0;

    static int in[N], trans[1 << N];
    for(int i = 0, tot = 0; i < 26; i ++) {
        for(int j = 0; j < L[i]; j ++)
            in[tot ++] = i;
    }
    memset(trans, 0, sizeof trans);
    for(int mask = 0; mask < (1 << least); mask ++) {
        for(int i = 0, tot = 0; i < 26; i ++) {
            int siz = 0;
            for(int j = 0; j < L[i]; j ++)
                siz += (mask >> tot & 1), tot ++;
            if(siz == L[i] && L[i] < R[i]) trans[mask] |= 1 << i;
        }
    }

    f[0][0] = 1;
    for(int i = 1; i <= n; i ++) {
        for(int mask = 0; mask < (1 << least); mask ++) if(f[i - 1][mask]) {
            for(int j = 0; j < least; j ++) if(!(mask >> j & 1) && (j == 0 || in[j] != in[j - 1] || (mask >> j - 1 & 1))) {
                int ch = in[j]; if(ban[i - 1] >> ch & 1) continue;
                f[i][mask | (1 << j)] = Plus(f[i][mask | (1 << j)], f[i - 1][mask]);
            }
            int T = trans[mask]; T = T ^ (T & ban[i - 1]);
            f[i][mask] = Plus(f[i][mask], 1ll * f[i - 1][mask] * __builtin_popcount(T) % MOD);
        }
    }
    return f[n][(1 << least) - 1];
}

int main() {
    ios::sync_with_stdio(false), cin.tie(0);

    int T = 1;// cin >> T;
    while(T --)
        cout << solve() << '\n';

    return 0;
}