#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define A 1111
const ll mod=1e9+7;
ll can[A][A][10],f[A][A][2],up[A][A],down[A][A];
//can定义为i行从1--j染成B剩下染成W是否合法
char ch[A][A];
ll n,m,flag1,flag2,ans;
int main(){scanf("%lld%lld",&n,&m);for(ll i=1;i<=n;i++)scanf("%s",ch[i]+1);for(ll i=1;i<=n;i++){ll maxpos=0;for(ll j=1;j<=m;j++){if(ch[i][j]=='W') break;if(ch[i][j]=='B') maxpos=j;}for(ll j=maxpos+1;j<=m;j++)if(ch[i][j]=='B'){maxpos=m+1;    break;}ll now=maxpos;while(ch[i][now]!='W'&&now<=m)can[i][now][1]=1,now++;}for(ll i=1;i<=n;i++){ll maxpos=m+1;for(ll j=m;j>=1;j--){if(ch[i][j]=='W') break;if(ch[i][j]=='B') maxpos=j;}for(ll j=maxpos-1;j>=1;j--)if(ch[i][j]=='B'){maxpos=-1; break;}ll now=maxpos;while(ch[i][now]!='W'&&now>=0)can[i][m-now+1][2]=1,now--;}for(ll i=0;i<=m;i++)up[0][i]=1,down[0][i]=1;for(ll i=1;i<=n;i++){for(ll j=0;j<=m;j++){if(!can[i][j][1]) continue;f[i][j][0]=up[i-1][j];f[i][j][1]=down[i-1][j];
//            printf("up[%lld][%lld]=%lld down=%lld\n",i-1,j,up[i-1][j],down[i-1][j]);
        }for(ll j=0;j<=m;j++)up[i][j]=(up[i][j-1]+f[i][j][0])%mod/*,printf("f=%lld up=%lld\n",f[i][j][0],up[i][j])*/;for(ll j=m;j>=0;j--)down[i][j]=(down[i][j+1]+f[i][j][1])%mod;
//        printf("up=%lld down=%lld\n",up[n][m],down[n][0]);
    }
/*    for(ll i=1;i<=n;i++,puts("")){for(ll j=1;j<=m;j++){printf("%lld ",can[i][j][1]);}}
*/    memset(f,0,sizeof(f));ans=(ans+up[n][m]+down[n][0]+mod)%mod;
//    printf("ans=%lld\n",ans);for(ll i=1;i<=n;i++){for(ll j=0;j<=m;j++){if(!can[i][j][2]) continue;f[i][j][0]=up[i-1][j];f[i][j][1]=down[i-1][j];}for(ll j=0;j<=m;j++)up[i][j]=(up[i][j-1]+f[i][j][0])%mod;for(ll j=m;j>=0;j--)down[i][j]=(down[i][j+1]+f[i][j][1])%mod;}
//    printf("up=%lld down=%lld\n",up[n][m],down[n][0]);ans=(ans+up[n][m]+down[n][0]+mod)%mod;
//    printf("ans=%lld\n",ans);memset(f,0,sizeof(f));//减去左右重复for(ll i=1;i<m;i++){ll flag=0;for(ll j=1;j<=n;j++)if(!can[j][i][1]){flag=1;break;}if(!flag) ans--;}for(ll i=1;i<m;i++){ll flag=0;for(ll j=1;j<=n;j++)if(!can[j][i][2]){flag=1;break;}if(!flag) ans--;}//减去上下//若上面为B下面只能为Wfor(ll i=1;i<n;i++){ll flag=0;for(ll j=1;j<=i;j++)if(!can[j][m][1]){flag=1;break;}for(ll j=i+1;j<=n;j++)if(!can[j][0][1]){flag=1;break;}if(flag)continue;ans--;}for(ll i=n;i>=2;i--){ll flag=0;for(ll j=1;j<=i-1;j++)if(!can[j][0][1]){flag=1;break;}for(ll j=i;j<=n;j++)if(!can[j][m][1]){flag=1;break;}if(flag)continue;ans--;}for(ll i=1;i<=n;i++){if(!can[i][0][1])    flag1=1;if(!can[i][m][1])    flag2=1;}if(!flag1) ans-=3;if(!flag2) ans-=3;printf("%lld\n",(ans+mod)%mod);
}

#include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>
#include<algorithm>
using namespace std;
#define R register
#define ll long long
inline ll read()//-------
{ll aa=0;char cc=getchar();while(cc<'0'||cc>'9') cc=getchar();while(cc<='9'&&cc>='0'){aa=(aa<<3)+(aa<<1)+(cc^48);cc=getchar();}return aa;
}
const int N=1000005;
struct tree{int v,last;
}tr[N<<1];
int tot,first[N];
inline void add(int x,int y)
{tr[++tot]=(tree){y,first[x]};first[x]=tot;return;
}
int n,ans,mp[N],vi[N];
int dfs(int x,int fa)
{int sum=0;vi[x]=1;for(R int i=first[x],v;i;i=tr[i].last){v=tr[i].v;if(v==fa)continue;dfs(v,x);sum^=1;if(!sum)++ans;}return sum;
}
int main()
{//freopen("tight.in","r",stdin);//freopen("tight.out","w",stdout);n=read();mp[1]=++mp[0];for(R int i=2,x,y,z;i<=n;++i){x=read();y=read();z=read();if(!z){if(mp[i])mp[x]=mp[i];else if(mp[x])mp[i]=mp[x];else mp[i]=mp[x]=++mp[0];continue;}if(!mp[i])mp[i]=++mp[0];if(!mp[x])mp[x]=++mp[0];if(y)continue;add(mp[i],mp[x]);add(mp[x],mp[i]);}for(R int i=1;i<=mp[0];++i)if(!vi[i])if(dfs(i,i))++ans;printf("%d",ans);return 0;
}