#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define per(i,a,b) for(int i=(a);i>=(b);--i)
#define fi first
#define sc second
using namespace std;
typedef long long LL;
typedef pair<int,int> pii;
bool _ST;
const int N=1e5+100,mod=1e9+7;
template<typename T>
void read(T &x){
	x=0;char c=getchar();
	while(c<'0'||c>'9') c=getchar();
	while('0'<=c&&c<='9'){x=(x<<1)+(x<<3)+(c&15);c=getchar();}
}
int n,m,v;
pii a[N];
LL ksm(LL a,LL b){
	LL res=1;for(;b;b>>=1,a=a*a%mod) if(b&1) res=res*a%mod;return res; 
}
void solve(){
	read(n),read(m),read(v);
	rep(i,1,m) read(a[i].fi),read(a[i].sc);
	sort(a+1,a+1+m,[](pii x,pii y){return x.fi<y.fi;});
	LL ans=1,tmp=1ll*v*v%mod;
	rep(i,1,m){
		if(i==1){
			int del=a[i].fi-1;
			ans=ans*ksm(tmp,del)%mod;
			continue;
		}
		if(a[i].fi==a[i-1].fi){
			if(a[i].sc!=a[i-1].sc){ans=0;break;}
			continue;
		}
		int del=a[i].fi-a[i-1].fi;
		LL ad=(ksm(tmp,del)+mod-1ll*ksm(v,del-1)*(v-1)%mod)%mod;
		ans=ans*ad%mod;
	}
	LL del=n-a[m].fi;
	ans=ans*ksm(tmp,del)%mod;
	printf("%lld\n",ans);
}
bool _ED;
signed main(){
	freopen("assign.in","r",stdin);
	freopen("assign.out","w",stdout);
	fprintf(stderr,"%.6lf MB\n",1.0*(&_ST-&_ED)/1024.0/1024.0);
	int T;read(T);
	while(T--) solve();
	fprintf(stderr,"%.6lf s\n",1.0*clock()/CLOCKS_PER_SEC);
	return 0;
}