#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,sse4.1,sse4.2,popcnt,abm,mmx,avx,avx2,fma")

#include <bits/stdc++.h>

using namespace std; const int maxn = 1e4 + 5, maxk = 19, mod = 1e9 + 7; typedef long long ll;

int n, k;

char s[maxk + 1], t[maxk + 1];

int mst[26], atl[26], eql[26], fbd[26];

int num[26];

int F[1 << maxk], G[maxk + 1][1 << maxk];

inline void get(int &x, int y) { if ((x += y) >= mod) x -= mod; }

int main()
{
    scanf("%d%d", &n, &k);
    for (int c = 0; c < 26; c++) eql[c] = -1;
    for (int i = 1; i <= n; i++)
    {
        scanf("%s%s", s, t);
        memset(num, 0, sizeof num);
        for (int j = 0; j < k; j++)
        {
            int c = s[j] - 'A';
            if (t[j] == 'O') num[c]++, mst[c] |= 1 << j;
        }
        for (int j = 0; j < k; j++)
        {
            int c = s[j] - 'A';
            if (t[j] == '-')
            {
                if (num[c] == -1) return 0 * puts("0");
                num[c]++;
                fbd[c] |= 1 << j;
            }
            else if (t[j] == 'x')
            {
                if (num[c] != -1)
                {
                    if (eql[c] != -1 && eql[c] != num[c]) return 0 * puts("0");
                    eql[c] = num[c];
                    num[c] = -1;
                }
                fbd[c] |= 1 << j;
            }
        }
        for (int j = 0; j < 26; j++) atl[j] = max(atl[j], num[j]);
    }
    F[0] = 1;
    for (int c = 0; c < 26; c++)
    {
        int r;
        if (eql[c] != -1)
        {
            if (atl[c] > eql[c]) return 0 * puts("0");
            r = eql[c];
            for (int i = 1; i <= r; i++) memset(G[i], 0, sizeof G[i]);
            memcpy(G[0], F, sizeof F);
            for (int j = 0; j < k; j++)
            {
                if (fbd[c] >> j & 1)
                {
                    if (mst[c] >> j & 1) return 0 * puts("0");
                    else continue;
                }
                else if (mst[c] >> j & 1)
                {
                    memset(G[r], 0, sizeof G[r]);
                    for (int i = r - 1; i >= 0; i--)
                    {
                        for (int S = 0; S < 1 << k; S++) if (!(S >> j & 1)) G[i + 1][S | (1 << j)] = G[i][S];
                        memset(G[i], 0, sizeof G[i]);
                    }
                }
                else
                {
                    for (int i = 0; i < r; i++) for (int S = 0; S < 1 << k; S++) if (!(S >> j & 1))  get(G[i + 1][S | (1 << j)], G[i][S]);
                }
            }
        }
        else
        {
            r = atl[c];
            for (int i = 1; i <= r; i++) memset(G[i], 0, sizeof G[i]);
            memcpy(G[0], F, sizeof F);
            for (int j = 0; j < k; j++)
            {
                if (fbd[c] >> j & 1)
                {
                    if (mst[c] >> j & 1) return 0 * puts("0");
                    else continue;
                }
                else if (mst[c] >> j & 1)
                {
                    for (int S = 0; S < 1 << k; S++) if (!(S >> j & 1)) G[r][S | (1 << j)] = G[r][S], G[r][S] = 0;
                    for (int i = r - 1; i >= 0; i--)
                    {
                        for (int S = 0; S < 1 << k; S++) if (!(S >> j & 1)) get(G[i + 1][S | (1 << j)], G[i][S]);
                        memset(G[i], 0, sizeof G[i]);
                    }
                }
                else
                {
                    for (int i = 0, ti; ti = min(i + 1, r), i <= r; i++) for (int S = 0; S < 1 << k; S++) if (!(S >> j & 1)) get(G[ti][S | (1 << j)], G[i][S]);
                }
            }
        }
        memcpy(F, G[r], sizeof F);
        bool fl = 0;
        for (int S = 0; S < 1 << k; S++) if (F[S]) { fl = 1; break; }
        if (!fl) break;
    }
    return 0 * printf("%d\n", F[(1 << k) - 1]);
}