#include<bits/stdc++.h>
using namespace std;
const int N=1e5+5;
constexpr int P=1e9+7;
int T,n,m,v;
pair<int,int> s[N];
inline int read(){
	int ret=0;char ch=getchar();
	while(ch<'0'||ch>'9')	ch=getchar();
	while(ch>='0'&&ch<='9')	ret=(ret<<1)+(ret<<3)+(ch^48),ch=getchar();
	return ret;
}
inline int power(int aa,int nn){
	int ret=1;
	for(;nn;nn>>=1,aa=1ll*aa*aa%P)	if(nn&1)	ret=1ll*ret*aa%P;
	return ret;
}
inline int fminus(int x,int y){
	return (x>=y?x-y:x+P-y);
}
int main(){
	freopen("assign.in","r",stdin);
	freopen("assign.out","w",stdout);
	T=read();
	while(T--){
		n=read(),m=read(),v=read();
		for(int i=1;i<=m;i++)	s[i].first=read(),s[i].second=read();
		sort(s+1,s+m+1);
		bool flag=1;
		for(int i=1;i<m;i++)	if(s[i].first==s[i+1].first&&s[i].second!=s[i+1].second){
			flag=0;
			break;
		}
		if(!flag)	cout<<0<<endl;
		else{
			if(!m)	cout<<power(v,2*(n-1))<<endl;
			else{
				int ans=power(v,2*(n-s[m].first+s[1].first-1));
				for(int i=1;i<m;i++){
					if(s[i].first==s[i+1].first)	continue;
					ans=1ll*ans*fminus(power(v,2*(s[i+1].first-s[i].first)),1ll*power(v,s[i+1].first-s[i].first-1)*(v-1)%P)%P;
				}
				cout<<ans<<endl;
			}
		}
	}
	return 0;
}