#include<bits/stdc++.h>
#define ll long long
using namespace std;

inline ll read(){
	ll s=0,k=1;
	char c=getchar();
	while(c>'9'||c<'0'){
		if(c=='-') k=-1;
		c=getchar();
	}
	while(c>='0'&&c<='9'){
		s=(s<<3)+(s<<1)+(c^48);
		c=getchar();
	}
	return s*k;
}

const int N=1e5+10,mod=1e9+7;
ll n,m,V;
struct que{
	ll c,d;
}qu[N];

ll ksm(ll a,ll b){
	ll t=1;
	for(;b>0;b>>=1,a=a*a%mod)
		if(b&1) t=t*a%mod;
	return t;
}

void Add(ll &x,ll y){
	x+=y;
	if(x>=mod) x-=mod;
}

void solve(){
	n=read();m=read();V=read();
	for(int i=1;i<=m;i++){
		qu[i].c=read();
		qu[i].d=read();
	}
	sort(qu+1,qu+1+m,[&](que x,que y){return x.c<y.c;});
	for(int i=1;i<=m;i++)
		if(qu[i].c==qu[i-1].c&&qu[i].d!=qu[i-1].d) return puts("0"),void();
	int tmp=m;
	m=0;
	for(int i=1;i<=tmp;i++)
		if(qu[i].c!=qu[i-1].c) qu[++m]=qu[i];
	ll ans=ksm(V,(qu[1].c-1)*2);
	for(int i=2;i<=m;i++){
		ll val=ksm(V,qu[i].c-qu[i-1].c-1);
		(val*=V-1)%=mod;
		val=mod-val;
		if(val>=mod) val-=mod;
		Add(val,ksm(V,(qu[i].c-qu[i-1].c)*2));
		(ans*=val)%=mod;
	}
	if(qu[m].c<n) (ans*=ksm(V,(n-qu[m].c)*2))%=mod;
	printf("%lld\n",ans);
}

int main(){
	freopen("assign.in","r",stdin);
	freopen("assign.out","w",stdout);
	int T=read();
	while(T--) solve();
	return 0;
}