#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N=1e5+2;
const int p=1e9+7;
int read()
{
	int x=0,f=1;char c=getchar();
	while(!isdigit(c)){if(c=='-')f=-1;c=getchar();}
	while(isdigit(c)){x=x*10+(c^48);c=getchar();}
	return x*f;
}
struct node
{
	int c,d;
	friend bool operator < (node a,node b)
	{
		return a.c<b.c;
	}
}a[N];
int n,m,v;
ll q_pow(ll a,ll b)
{
	ll ret=1;
	while(b)
	{
		if(b&1)
			ret=ret*a%p;
		a=a*a%p;
		b>>=1;
	}
	return ret;
}
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].c=read(),a[i].d=read();
		sort(a+1,a+1+m);
		bool flag=false;
		for(int i=2;i<=m;i++)
		{
			if(a[i].c==a[i-1].c&&a[i].d!=a[i-1].d)
			{
				flag=true;
				break;
			}
		}
		if(flag)
		{
			cout<<0<<endl;
			continue;
		}
		ll ans=q_pow(v,2*(a[1].c-1));
		for(int i=2;i<=m;i++)
		{
			int len=a[i].c-a[i-1].c;
			if(len==0)
				continue;
			ans=ans*(q_pow(v,2*len)-q_pow(v,len-1)*(v-1)%p+p)%p;
		}
		ans=ans*q_pow(v,2*(n-a[m].c))%p;
		cout<<ans<<endl; 
	}
}