#pragma GCC Optimize("Ofast")
#include<bits/stdc++.h>
using namespace std;
const int maxn=1e3+5,mod=1e9+7;
#define pb push_back
inline int read(){
    char ch=getchar();int x=0;bool f=0;
    for(;!isdigit(ch);ch=getchar())if(ch=='-'){f=1;}
    for(;isdigit(ch);ch=getchar())x=(x<<1)+(x<<3)+(ch^48);
    if(f==1)x=-x;
    return x;
}
int n,m,k,T;
int least[maxn],cnt[maxn];
int g[maxn][37];
char s1[maxn],b[maxn];
int c[maxn],a[maxn];
typedef unsigned long long ull;
const ull Base=233;
unordered_map<ull,int>f[27];
ull pw[27];
int dfs(int x,vector<int> &tmp,ull hash,int u){
	if(x==m+1&&!u)return 1;
	if(x==m+1&&u)return 0;
	if(x+u>m+1)return 0;
	if(f[x].find(hash)!=f[x].end()){return f[x][hash];}
	int sum=0;
	if(c[x]!=-1){
		if(tmp[c[x]]){
			tmp[c[x]]--;
			hash-=pw[c[x]];
			sum=(sum+dfs(x+1,tmp,hash,u-1))%mod;
			tmp[c[x]]++;
			hash+=pw[c[x]];
		}
		else if(cnt[c[x]]==-1){
			sum=(sum+dfs(x+1,tmp,hash,u))%mod;
		}
	}
	else{
		for(int i=0;i<26;i++){
			if(!g[x][i]){
				if(tmp[i]){
					tmp[i]--;
					hash-=pw[i];
					sum=(sum+dfs(x+1,tmp,hash,u-1))%mod;
					tmp[i]++;
					hash+=pw[i];
				}
				else if(cnt[i]==-1){
					//cout<<i<<endl;
					sum=(sum+dfs(x+1,tmp,hash,u))%mod;
				}
			}
		}
	}
	sum%=mod;
	f[x][hash]=sum;
	return sum;
}
signed main(){
	pw[0]=1; for(int i=1;i<=26;i++) pw[i]=pw[i-1]*Base;
    n=read(),m=read();
	for(int i=0;i<26;i++)cnt[i]=-1,c[i]=-1;
	for(int i=1;i<=n;i++){
		scanf("%s",s1+1);
		scanf("%s",b+1);
		vector<int>tmp,flag;
		tmp.resize(29);flag.resize(29);
		for(int j=1;j<=m;j++)a[j]=s1[j]-'A';
		for(int j=1;j<=m;j++)
			if(b[j]=='O'){
				if(flag[a[j]]){puts("0");return 0;}
				if(g[j][a[j]]){
					puts("0");return 0;
				}
				tmp[a[j]]++;
				if(c[j]==-1){
					c[j]=a[j];
				}
				else if(c[j]!=a[j]){
					puts("0");return 0;
				}
			}
		for(int j=1;j<=m;j++){
			//cout<<i<<" "<<j<<endl;
			
			if(b[j]=='-'){
				if(c[j]!=-1&&c[j]==a[j]){puts("0");return 0;}
				if(flag[a[j]]){puts("0");return 0;}
				g[j][a[j]]=1;tmp[a[j]]++;

			}
			if(b[j]=='x'){
				if(c[j]!=-1&&c[j]==a[j]){puts("0");return 0;}
				flag[a[j]]=1;
				g[j][a[j]]=1;
				if(least[a[j]]>tmp[a[j]]){
					puts("0");return 0;
				}
				if(cnt[a[j]]>=0){
					if(cnt[a[j]]!=tmp[a[j]]){
						puts("0");return 0;
					}
				}
				else{
					cnt[a[j]]=tmp[a[j]];
					least[a[j]]=tmp[a[j]];
				}
			}
			
		}
		for(int j=0;j<26;j++){
			if(tmp[j]>cnt[j]&&cnt[j]>=0){
				puts("0");return 0;
			}
			least[j]=max(least[j],tmp[j]);
		}
	}
	vector<int>tmp;tmp.clear();tmp.resize(26);
	int s=0;
	ull hash=0;
	for(int i=0;i<26;i++){
		tmp[i]=least[i];s+=least[i];
		hash+=tmp[i]*pw[i];
	}
	cout<<dfs(1,tmp,hash,s)<<endl;
}