#include<bits/stdc++.h>
using namespace std;
namespace io{
	char buf[1<<20],*p1=buf,*p2=buf;
#define gc() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<20,stdin)),p1==p2?EOF:*p1++)
	int read(){
		int x=0,f=0;char c=gc();
		while(c< '0'||c> '9') f|=c=='-',c=gc();
		while(c>='0'&&c<='9') x=x*10+(c^48),c=gc();
		return f?-x:x;
	}
	char pbuf[1<<20],*pp=pbuf;
#define flush() (fwrite(pbuf,1,pp-pbuf,stdout),pp=pbuf)
#define pc(ch) (pp==pbuf+(1<<20)&&flush(),*pp++=(ch))
	class Flush{public:~Flush(){flush();}}_;
	void write(int x,char ch=0){
		if(x<0) pc('-'),x=-x;
		static int st[35];int top=0;
		do st[top++]=x%10,x/=10;while(x);
		while(top) pc(st[--top]^48);if(ch) pc(ch);
	}
	void putc(char ch){pc(ch);}
}
#define N 100009
#define ll long long
const int mo=1000000007;
int qp(int a,int b){
	int r=1;
	for(;b;b>>=1,a=(ll)a*a%mo)
		if(b&1) r=(ll)r*a%mo;
	return r;
}
pair<int,int>a[N];
void solve(){
	int n,m,v;
	n=io::read();
	m=io::read();
	v=io::read();
	for(int i=1;i<=m;i++){
		a[i].first=io::read();
		a[i].second=io::read();
	}
	sort(a+1,a+m+1);
	int ans=1;
	for(int i=1;i<m;i++)
		if(a[i].first==a[i+1].first&&a[i].second!=a[i+1].second)
			return io::write(0,'\n');
	for(int i=1;i<m;i++){
		int x=a[i+1].first-a[i].first;
		if(!x) continue;
		int tmp=0;
		tmp=qp((ll)v*v%mo,x);
		tmp-=(ll)qp(v,x-1)*(v-1)%mo;
		if(tmp<0) tmp+=mo;
		ans=(ll)ans*tmp%mo;
	}
	ans=(ll)ans*qp((ll)v*v%mo,a[1].first-1)%mo;
	ans=(ll)ans*qp((ll)v*v%mo,n-a[m].first)%mo;
	io::write(ans,'\n');
}
int main(){
	freopen("assign.in","r",stdin);
	freopen("assign.out","w",stdout);
	int t;
	t=io::read();
	while(t--) solve();
	return 0;
}