#include<bits/stdc++.h>
using namespace std;
constexpr int N=1e5+9,S=1<<22,mod=1e9+7;
char buf[S],*p1,*p2;
inline int nc(){
	if(p1==p2){
		p2=(p1=buf)+cin.read(buf,S).gcount();
		if(p1==p2)return EOF;
	}return *p1++;
}
inline int rd(){
	char ch;
	while(!isdigit(ch=nc()));
	int x=ch&0xf;
	while(isdigit(ch=nc()))x=x*10+(ch&0xf);
	return x;
}
int n,m,v,a[N],ans;
pair<int,int>res[N];
inline void mul(int&x,int y){
	x=1ll*x*y%mod;
}
inline int qpow(int x,int pw,int v=1){
	while(pw){
		if(pw&1)mul(v,x);
		pw>>=1,mul(x,x);
	}return v;
}
bool chk(){
	sort(res+1,res+m+1);
	m=unique(res+1,res+m+1)-res-1;
	for(int i=1;i<=m;++i){
		int x=a[i]=res[i].first;
		if(i&&x==a[i-1])return false;
	}
	return true;
}
signed main(){
	freopen("assign.in","r",stdin);
	freopen("assign.out","w",stdout);
	cin.tie(nullptr)->sync_with_stdio(false);
	for(int T=rd();T;--T){
		n=rd(),m=rd(),v=rd();
		for(int i=1;i<=m;++i)
			res[i].first=rd(),res[i].second=rd();
		if(!chk()){
			cout<<0<<'\n';
			continue;
		}
		ans=qpow(v,((a[1]-1)+(n-a[m]))<<1);
		for(int i=1;i<m;++i){
			int tot=qpow(v,(a[i+1]-a[i])<<1);
			int dt=qpow(v,a[i+1]-a[i]-1,v-1);
			mul(ans,tot-dt);
		}
		if(ans<0)ans+=mod;
		cout<<ans<<'\n';
	}
	return cout<<flush,0;
}