#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<algorithm>
#include<random>
#include<chrono>
#include<vector>
#include<queue>
#include<map>
using namespace std;
using namespace chrono;
bool Mbe;
bool File(string Name)
{
	string In=Name+".in",Out=Name+".out";
	freopen(In.c_str(),"r",stdin);
	freopen(Out.c_str(),"w",stdout);
	return true;
}
bool fle=File("assign");
template<typename T> void Debug(T s)
{
	cerr<<s<<endl;
}
template<typename T,typename... Args> void Debug(T s,Args... args)
{
	cerr<<s;
	Debug(args...);
}
typedef long long Type; // change here
Type rd(){Type s=0;int f=1;char ch=getchar();while(ch<'0' || ch>'9'){if(ch=='-')f=-1;ch=getchar();}while(ch>='0' && ch<='9'){s=s*10+ch-'0';ch=getchar();}return s*f;}void rd(Type &x){x=rd();}template<typename... Args>void rd(Type &x,Args&... args){rd(x);rd(args...);}void rdArr(Type *arr,int Len){for(int i=1;i<=Len;i++)rd(arr[i]);}void wr(Type x){if(x<0)putchar('-'),x=-x;if(x>9)wr(x/10);putchar(x%10+'0');}void wr_space(Type x){wr(x);putchar(' ');}void wr_endl(Type x){wr(x);putchar('\n');}void wrArr(Type *arr,int Len){for(int i=1;i<Len;i++)wr_space(arr[i]);wr_endl(arr[Len]);}
const long long M=1000000007;
long long T=rd(),n,m,v;
struct P
{
	long long c,d;
	bool operator<(const P &o)const
	{
		return c<o.c;
	}
	bool operator==(const P &o)const
	{
		return c==o.c;
	}
}p[200001];
long long qpow(long long b,long long p)
{
	long long res=1;
	while(p)
	{
		if(p&1)
		res=res*b%M;
		b=b*b%M;
		p>>=1;
	}
	return res;
}
void Input()
{
	long long ret=1;
	rd(n,m,v);
	for(int i=1;i<=m;i++)
	rd(p[i].c,p[i].d);
	sort(p+1,p+m+1);
//	int st=0,ed=0;
	p[0].c=p[m+1].c=-1;
	for(int i=1;i<=m;i++)
	{
		if(p[i].c==p[i-1].c && p[i].d!=p[i-1].d)
		return wr_endl(0);
	}
	m=unique(p+1,p+m+1)-p-1;
	p[m+1].c=-1;
//	Debug(m);
//	for(int i=1;i<=m;i++)
//	Debug(p[i].c," ",p[i].d);
	for(int i=2;i<=m;i++)
	ret=ret*(qpow(v*v%M,p[i].c-p[i-1].c)-qpow(v,p[i].c-p[i-1].c-1)%M*(v-1)%M+M)%M;
//	ret=(qpow(v*v%M,ret)-qpow(V,ret)+M)%M*qpow(v*v%M,n-1-ret)%M;
//	wr_endl((qpow(v*v%M,n-1)-ret+M)%M);
	if(m>1)
	wr_endl(ret*qpow(v*v%M,(p[1].c-1+n-p[m].c+M)%M)%M);
	else
	wr_endl(qpow(v*v%M,n-1)); 
}
void Solve()
{
	// Hello
}
void Output()
{
	// Hello
}
bool Med;
int main()
{
	fprintf(stderr,"%0.3lf MiB\n",(&Mbe-&Med)/1048576.0);
	while(T--)
	Input();
	Solve();
	Output();
	return 0;
}
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/*
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qpow(v*v%M,ed-st)-qpow(V,ed-st)
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*/