#include<bits/stdc++.h>
#define int long long
#define ffor(i,a,b) for(int i=(a);i<=(b);i++)
#define roff(i,a,b) for(int i=(a);i>=(b);i--)
using namespace std;
const int MAXN=1e5+10,MAXM=1050,MAXK=(1<<20)+10,MOD=1e9+7;
int Mx=(1<<20)+4,n,m,fuc[MAXK],inv[MAXK],val[MAXK],cnt[MAXK],wys[MAXK],dp[MAXM][MAXM],tmp[MAXM];
int qpow(int base,int p) {
	int ans=1;
	while(p) {
		if(p&1) ans*=base,ans%=MOD;
		base*=base,base%=MOD,p>>=1;
	}
	return ans;
}
int C(int u,int d) {
	return fuc[d]*inv[u]%MOD*inv[d-u]%MOD;	
}
signed main() {
	ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
	fuc[0]=1; ffor(i,1,Mx) fuc[i]=fuc[i-1]*i%MOD;
	inv[Mx]=qpow(fuc[Mx],MOD-2);
	roff(i,Mx-1,0) inv[i]=inv[i+1]*(i+1)%MOD;
	cin>>n>>m;
	ffor(i,1,m) {
		string S; cin>>S; S="&"+S;
		ffor(j,1,n) if(S[j]=='H') val[j]+=(1<<i-1);
	}
	ffor(i,1,n) cnt[val[i]]++;
	ffor(i,0,Mx) ffor(j,1,cnt[i]) wys[i]=(wys[i]+C(j,cnt[i])*fuc[j]%MOD)%MOD;
	int U=(1<<10)-1,ans=0;
	ffor(i,0,U) tmp[i]=1;
	ffor(i,0,U) {
		ffor(j,0,U) {
			dp[i][j]=1;
			ffor(k,0,i-1) if((k&i)==k) dp[i][j]=(dp[i][j]+dp[k][j])%MOD;
			dp[i][j]=dp[i][j]*wys[i*U+j]%MOD;
		}
		ffor(j,0,U) {
			int tot=0;
			ffor(k,0,j) if((k&j)==k) tot=(tot+dp[i][k])%MOD;
			tot=(tot-dp[i][j])%MOD;
			tot=tot*wys[i*U+j]%MOD;
			dp[i][j]=(dp[i][j]+tot)%MOD;
		} 
		ffor(j,0,9) ffor(k,0,U-(1<<j)) if(!(k&(1<<j))) dp[i][k+(1<<j)]=(dp[i][k+(1<<j)]+dp[i][k])%MOD;
		ans=(ans+dp[i][U])%MOD;
	}
	cout<<(ans%MOD+MOD)%MOD<<"\n";
	return 0;
}