#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
#define ll long long
//#define int long long
#define ull unsigned long long
#define SZ(x) ((int)((x).size()))
#define ALL(x) (x).begin(),(x).end()
using namespace std;
inline int read()
{
    char c=getchar();int x=0;bool f=0;
    for(;!isdigit(c);c=getchar())f^=!(c^45);
    for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
    if(f)x=-x;return x;
}

#define mod 1000000007
struct modint{
	int x;
	modint(int o=0){x=o;}
	modint &operator = (int o){return x=o,*this;}
	modint &operator +=(modint o){return x=x+o.x>=mod?x+o.x-mod:x+o.x,*this;}
	modint &operator -=(modint o){return x=x-o.x<0?x-o.x+mod:x-o.x,*this;}
	modint &operator *=(modint o){return x=1ll*x*o.x%mod,*this;}
	modint &operator ^=(int b){
		modint a=*this,c=1;
		for(;b;b>>=1,a*=a)if(b&1)c*=a;
		return x=c.x,*this;
	}
	modint &operator /=(modint o){return *this *=o^=mod-2;}
	friend modint operator +(modint a,modint b){return a+=b;}
	friend modint operator -(modint a,modint b){return a-=b;}
	friend modint operator *(modint a,modint b){return a*=b;}
	friend modint operator /(modint a,modint b){return a/=b;}
	friend modint operator ^(modint a,int b){return a^=b;}
	friend bool operator ==(modint a,modint b){return a.x==b.x;}
	friend bool operator !=(modint a,modint b){return a.x!=b.x;}
	bool operator ! () {return !x;}
	modint operator - () {return x?mod-x:0;}
	bool operator <(const modint&b)const{return x<b.x;}
};
inline modint qpow(modint x,int y){return x^y;}

vector<modint> fac,ifac,iv;
inline void initC(int n)
{
	if(iv.empty())fac=ifac=iv=vector<modint>(2,1);
	int m=iv.size(); ++n;
	if(m>=n)return;
	iv.resize(n),fac.resize(n),ifac.resize(n);
	For(i,m,n-1){
		iv[i]=iv[mod%i]*(mod-mod/i);
		fac[i]=fac[i-1]*i,ifac[i]=ifac[i-1]*iv[i];
	}
}
inline modint C(int n,int m){
	if(m<0||n<m)return 0;
	return initC(n),fac[n]*ifac[m]*ifac[n-m];
}
inline modint sign(int n){return (n&1)?(mod-1):(1);}

#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;

#define maxn 1000005
#define inf 0x3f3f3f3f

int n,m,n1,n2;
vi e[maxn];

int dfn[maxn],low[maxn],idx,scc,st[maxn],tp,bel[maxn];
vi p[maxn];

void tar(int u){
	dfn[u]=low[u]=++idx;
	st[++tp]=u;
	for(int v:e[u]){
		if(!dfn[v])tar(v),low[u]=min(low[u],low[v]);
		else if(!bel[v])low[u]=min(low[u],dfn[v]);
	}
	if(dfn[u]!=low[u])return;
	int v; ++scc; do{
		v=st[tp--];
		bel[v]=scc;
		p[scc].pb(v);
	}while(u!=v);
}

int id[maxn],cnt;
int l[maxn],r[maxn];

pii get(vector<pii>o){
	if(!o.size()) return {-1,-1};
	sort(o.begin(),o.end());
	int l=-inf,r=-inf;
	vector<pii>res;
	for(auto [x,y]:o){
		if(x>r+1){
			if(l!=-inf)res.pb(mkp(l,r));
			l=x,r=y;
		}
		else r=max(r,y);
	}
	res.pb(mkp(l,r));
	if(res.size()==1) return res[0];
//	cout<<"res "<<"\n";
//	for(auto [x,y]:res)cout<<x<<" "<<y<<"\n";
//	assert(res.size()==2);
	if(res[0].fi==1 && res[1].se==cnt); else exit(3);
	return mkp(res[1].fi,res[0].se);
}

bool vis[maxn];
int t[maxn],len;

int Len(int l,int r){
	if(l<=r)return r-l+1;
	return (cnt-l+1)+r;
}

modint f[maxn],sf[maxn],pw[maxn];
bool havp[maxn],ban[maxn];

int mx1[maxn],mx2[maxn];

signed main()
{
//	freopen("wys2d.in","r",stdin);
//	freopen("my.out","w",stdout);
	n=read(),m=read(),n1=read(),n2=read();
	For(i,1,m){
		int u=read();
		string w;cin>>w;
		int v=read();
		e[u].pb(v);
		if(w=="--")e[v].pb(u);
	}
	For(i,1,n1) if(!dfn[i]) tar(i);
	
	int pres=0;
	For(i,n1+1,n1+n2)
		if(dfn[i]) id[i]=++cnt;
		else ++pres;
	
	// [1,n1] --> [n1+1,n1+n2]
	For(i,1,scc) {
		vector<pii>o;
		for(int u:p[i]){
			if(u>n1 && u<=n1+n2) o.pb(mkp(id[u],id[u]));
			for(int v:e[u]){
				int x=bel[v];
				if(vis[x] || x==i)continue;
				vis[x]=1;
			//	cout<<"x: "<<x<<" "<<l[x]<<' '<<r[x]<<"\n";
				if(l[x]==-1)continue;
				if(l[x]<=r[x])o.pb(mkp(l[x],r[x]));
				else o.pb(mkp(1,r[x])),o.pb(mkp(l[x],cnt));
			}
		}
		pii t=get(o);
		l[i]=t.fi,r[i]=t.se;
		for(int u:p[i]) for(int v:e[u]) vis[bel[v]]=0;
	}
	
	int mn=inf,ml=0,mr=0;
	For(i,1,n1) havp[bel[i]]=1;
	For(i,1,scc) if(havp[i] && Len(l[i],r[i])<mn) mn=Len(l[i],r[i]),ml=l[i],mr=r[i];
	vector< array<int,3> >vec;
	
//	cout<<"cnt "<<cnt<<"\n";
//	cout<<"pres "<<pres<<"\n";
	int add=ml;
	For(i,1,scc) if(havp[i]) {
		l[i]=(l[i]-ml+cnt)%cnt+1;
		r[i]=(r[i]-ml+cnt)%cnt+1;
		if(l[i]<=r[i]) vec.pb({l[i],r[i],i}),vec.pb({l[i]+cnt,r[i]+cnt,i});
		else vec.pb({l[i],r[i]+cnt,i});
	//	cout<<"i: "<<i<<" "<<l[i]<<" "<<r[i]<<"\n";
	}
	ml=(ml-add+cnt)%cnt+1;
	mr=(mr-add+cnt)%cnt+1;
	
	sort(vec.begin(),vec.end(),[&](auto x,auto y){
		if(x[0]!=y[0]) return x[0]<y[0];
		if(x[1]!=y[1]) return x[1]>y[1];
		return x[2]<y[2]; // important
	});
	reverse(vec.begin(),vec.end());
	 
	mn=inf;
	for(auto p:vec){
		if(p[1]>=mn)ban[p[2]]=1;
		mn=min(mn,p[1]);
	}
	
	t[++len]=0;
	t[++len]=cnt;
	For(i,1,scc) if(havp[i] && !ban[i]) t[++len]=l[i]-1,t[++len]=r[i];
	sort(t+1,t+len+1),len=unique(t+1,t+len+1)-t-1;
	#define V(x) lower_bound(t+1,t+len+1,x)-t
	For(i,1,scc) if(havp[i] && !ban[i]) {
		l[i]=V(l[i]-1),r[i]=V(r[i]);
		if(l[i]<=r[i]) mx1[r[i]]=max(mx1[r[i]],l[i]);
		else mx2[r[i]]=max(mx2[r[i]],l[i]);
	}
	mr=V(mr);
	
	pw[0]=1;
	For(i,1,n)pw[i]=pw[i-1]*2;
	
	modint res=0;
	For(i,2,mr){
		For(j,0,len) f[j]=sf[j]=0;
		f[i]=sf[i]=pw[t[i]-t[i-1]]-1;
		int mx=1;
		For(j,i+1,len){
			f[j]=(sf[j-1]-sf[mx])*(pw[t[j]-t[j-1]]-1);
			sf[j]=sf[j-1]+f[j];
			mx=max(mx,mx1[j]);
		}
		res+=sf[len]-sf[mx];
		mx1[len]=max(mx1[len],mx2[i]);
	}
	
	res*=qpow(2,pres);
	cout<<res.x;
	return 0;
}