#include<bits/stdc++.h>
#define mod 1000000007
using namespace std;
char ib[1<<24],*ip1=ib,*ip2=ib;
#define gc() (ip1==ip2&&(ip2=(ip1=ib)+fread(ib,1,1<<24,stdin)),ip1==ip2?EOF:*ip1++)
inline int read(){
	int x=0;char c=gc();
	while(c<'0'||c>'9')c=gc();
	while(c>='0'&&c<='9')x=(x<<3)+(x<<1)+(c^'0'),c=gc();
	return x;
}
int powdv(int x,int y=mod-2){
	int ans=1;
	while(y){
		if(y&1)ans=1ll*ans*x%mod;
		y>>=1,x=1ll*x*x%mod;
	}
	return ans;
}
pair<int,int>pi[100005];
int main(){
	freopen("assign.in","r",stdin);
	freopen("assign.out","w",stdout);
	int T=read();
	while(T--){
		int n=read(),m=read(),v=read();
		for(int i=1;i<=m;++i){
			pi[i].first=read(),pi[i].second=read();
		}
		sort(pi+1,pi+m+1);
		int ans=1;
		ans=1ll*ans*powdv(1ll*v*v%mod,pi[1].first-1)%mod;
		for(int i=1;i<m;++i){
			int x=pi[i].first,y=pi[i+1].first;
			if(x==y){
				if(pi[i].second!=pi[i+1].second)ans=0;
				continue;
			}
			int k=y-x;
			ans=(0ll+powdv(1ll*v*v%mod,k)-1ll*(v-1)*powdv(v,k-1)%mod+mod)*ans%mod;
		}
		ans=1ll*ans*powdv(1ll*v*v%mod,n-pi[m].first)%mod;
		printf("%d\n",ans);
	}
	return 0;
}