#include<bits/stdc++.h>
using namespace std;
#define int long long
const int M=1e5+5,mod=1e9+7; 
int read(){
	int num=0,typ=1,c=getchar();
	while('0'>c||c>'9'){
		if(c=='-') typ=-1;
		c=getchar();
	}while('0'<=c&&c<='9'){
		num=num*10+c-48;
		c=getchar(); 
	}return num*typ;
}
int t;
int n,m,v,ans,res[M];
int qpow(int x,int y){
	int ans=1;
	while(y){
		if(y&1) (ans*=x)%=mod;
		(x*=x)%=mod;
		y>>=1;
	}return ans;
}
pair<int,int>p[M];
signed main(){
	freopen("assign.in","r",stdin);
	freopen("assign.out","w",stdout);
	for(t=read();t;t--){
		n=read();m=read();v=read();
		for(int i=1;i<=m;i++){
			p[i].first=read();
			p[i].second=read();
		}
		sort(p+1,p+m+1);
		m=unique(p+1,p+m+1)-p-1;
		res[m]=0;
		ans=qpow(v*v%mod,n-p[m].first);
		for(int i=m-1;i>=1;i--){
			if(p[i].first==p[i+1].first){
				ans=0;
				break;
			}
			res[i]=(qpow(v*v%mod,p[i+1].first-p[i].first)-(qpow(v,p[i+1].first-p[i].first-1)*(v-1))%mod+mod)%mod;
			(ans*=res[i])%=mod;
		}
		(ans*=qpow(v*v%mod,p[1].first-1))%=mod;
		printf("%lld\n",ans);
	}
	return 0;
}