#include<bits/stdc++.h>
#define ll long long
#define pb push_back
#define fi first
#define se second
#define endl '\n'
#define debug(x) cerr<<#x<<":"<<x<<endl
using namespace std;
ll read(){
	ll s=0,f=1;char ch=getchar();
	while(!isdigit(ch)){if(ch=='-') f=-1;ch=getchar();}
	while(isdigit(ch)){s=(s<<1)+(s<<3)+(ch^48);
		ch=getchar();}
	return s*f;
}
void write_(ll x){
	if(x<0){putchar('-');x=-x;}
	if(x>9){write_(x/10);}putchar((x%10)^48);return;
}
void write(ll x){write_(x);putchar('\n');return;}
void getmax(ll &x,ll y){
	if(y>x) x=y;
	return;
}
void getmin(ll &x,ll y){
	if(y<x) x=y;
	return;
}
const ll MOD=1e9+7;
ll kmi(ll a,ll b){
	a%=MOD;
	ll res=1;
	while(b){
		if(b&1) res=res*a%MOD;
		a=a*a%MOD;
		b>>=1;
	}
	return res;
}
void getadd(ll &x,ll y){
	x+=y;
	if(x>=MOD) x-=MOD;
	return;
}
int T;
ll n,m;
ll V;
struct node{
	ll x,y;
	bool operator < (const node &w) const{
		return x<w.x;
	}
}t[100005];

int main(){
	freopen("assign.in","r",stdin);
	freopen("assign.out","w",stdout);
	cin>>T;
	while(T--){
		n=read(),m=read(),V=read();
		for(int i=1;i<=m;++i){
			t[i].x=read(),t[i].y=read();
		}
		sort(t+1,t+m+1);
		bool flag=1;
		for(int i=2;i<=m;++i){
			if(t[i].x==t[i-1].x&&t[i].y!=t[i-1].y){
				flag=0;
				break;
			}
		}
		if(!flag){
			puts("0");
			continue;
		}
		int tm=1;
		for(int i=2;i<=m;++i){
			if(t[i].x!=t[tm].x) t[++tm]=t[i];
		}
		m=tm;
		ll ans=0;
		ans=kmi(V*V%MOD,t[1].x-1);
		for(int i=1;i<m;++i){
			ll res=(MOD-kmi(V,t[i+1].x-t[i].x-1)*(V-1)%MOD)%MOD;
			getadd(res,kmi(V*V%MOD,t[i+1].x-t[i].x));
			ans=ans*res%MOD;
		}
		ans=ans*kmi(V*V,n-t[m].x)%MOD;
		cout<<ans<<endl;
	}
	
	return 0;
}
/*



*/