#include<bits/stdc++.h>
using namespace std;
#define ll long long
const int SZ=1<<20;
char buf[SZ],*p1,*p2;
#define gc() (p1==p2&&(p2=(p1=buf)+fread(buf,1,SZ,stdin),p1==p2)?EOF:*p1++)
ll read(){
	ll n=0; bool m=0;
	char c=gc();
	while(c<'0'||c>'9')m=c=='-',c=gc();
	while(c>='0'&&c<='9')n=(n<<3)+(n<<1)+(c^'0'),c=gc();
	return m?-n:n;
}
const int N=1e5+5,mod=1e9+7;
int pw(int x,int y=mod-2){
	int z=1;
	while(y){
		if(y&1)z=(ll)z*x%mod;
		y>>=1,x=(ll)x*x%mod;
	}
	return z;
}
int n,m,v;
pair<int,int>a[N];
bool init(){
	sort(a+1,a+m+1),m=unique(a+1,a+m+1)-a-1;
	for(int i=1;i<m;i++){
		if(a[i].first==a[i+1].first)return 1;
	}
	return 0;
}
int main(){
	freopen("assign.in","r",stdin);
	freopen("assign.out","w",stdout);
	int T=read();
	while(T--){
		n=read(),m=read(),v=read();
		for(int i=1;i<=m;i++)a[i].first=read(),a[i].second=read();
		if(init()){
			printf("0\n");
			continue;
		}
		int ans=(ll)pw(v,a[1].first-1<<1)*pw(v,n-a[m].first<<1)%mod;
		for(int i=1;i<m;i++){
			int x=a[i+1].first-a[i].first;
			ans=(ll)ans*(pw(v,x<<1)-(ll)pw(v,x-1)*(v-1)%mod+mod)%mod;
		}
		printf("%d\n",ans);
	}
	return 0;
}