#include <bits/stdc++.h> 
using namespace std;
int n,m,v;
map<int,int> a;
const long long p=1e9+7;
long long dp[1000005][2];
int qpow(int x,int y)
{
	int now=x,k=y;
	int ans=1;
	while(k)
	{
		if(k%2)
			ans=1ll*ans*now%p;
		k/=2;
		now=1ll*now*now%p;
	}
	return ans;
}
void sloveA()
{
	int now=((1ll*(v-1)*v%p)+1)%p,k=n-1;
	cout<<qpow(now,k)<<"\n";
}
void slove1()//���Ե�6~9 
{
	cout<<qpow(v,n*2-2)<<"\n";
}
void mian()
{
	cin>>n>>m>>v;
	a.clear();
	bool defeat=false;
	for(int i=1;i<=m;i++)
	{
		int u,v;
		cin>>u>>v;
		if(!a.count(u)||a[u]==v)
			a[u]=v;
		else
			defeat=true;
	}
	if(defeat)
	{
		cout<<"0\n";
		return ;
	}
	bool isA=(a.size()==n);
	if(isA)
	{
		sloveA();
		return ;
	}
	bool is1=(a.size()==1);
	if(is1)
	{
		slove1();
		return ;
	}
	for(int i=1;i<=n;i++)
		dp[i][0]=dp[i][1]=0;
	if(a.count(1))
		dp[1][1]=1;
	else
		dp[1][0]=1;
	for(int i=1;i<=n;i++)
	{
		if(a.count(i))
		{
			dp[i][1]+=dp[i][0];
			dp[i][0]=0;
		}
		dp[i+1][0]=(dp[i+1][0]+1ll*dp[i][0]*v%p*v%p)%p;
		
		dp[i+1][0]=(dp[i+1][0]+1ll*dp[i][1]*v%p*(v-1))%p;
		dp[i+1][1]=(dp[i+1][1]+dp[i][1]);
		if(!a.count(i+1))
			dp[i+1][1]=(1ll*dp[i][1]*v)%p;
	}
	cout<<(dp[n][0]+dp[n][1])%p<<"\n";
	return ;
}
int main()
{
	freopen("assign.in","r",stdin);
	freopen("assign.out","w",stdout);
	int t;
	cin>>t;
	for(int i=1;i<=t;i++)
		mian();
	return 0;
}