#include<bits/stdc++.h>
#define int long long
#define MX 100005
#define GP pair<int,int>
#define MP make_pair
using namespace std;int read();
const int mod=1000000007;
int qpow(int x,int y){
	int z=1;while(y){
		if(y&1) z=z*x%mod;
		x=x*x%mod;y>>=1;
	}return z;
}
GP w[MX];
int n,m,M,v,p[MX];
signed main(){
	freopen("assign.in","r",stdin);
	freopen("assign.out","w",stdout);
	int T=read();while(T--){
		n=read();M=read();v=read();
		for(int i=1;i<=M;i++){
			w[i].first=read();
			w[i].second=read();
		}sort(w+1,w+1+M);
		int F=1;m=0;
		for(int i=1;i<=M;i++){
			if(w[i].first==w[i-1].first){
				if(w[i].second!=w[i-1].second) F=0;
			}else{
				p[++m]=w[i].first;
			}
		}
		if(!F){printf("0\n");continue;}
		int res=qpow(v,n-p[m]+p[1]-1)%mod;
		res=(res*res)%mod;
		for(int i=2;i<=m;i++){
			int cnt=qpow(v,p[i]-p[i-1]-1);
			int ans=cnt;cnt=(cnt*v)%mod;
			ans=(ans+cnt*(cnt-1))%mod;
			res=(res*ans)%mod;
		}printf("%lld\n",res);
	}
	return 0;
}
int read(){
	int Ca=0,Cf=1;char Cr=' ';
	while(Cr<'0' || Cr>'9'){Cr=getchar();if(Cr=='-'){Cf=-Cf;}}
	while(Cr>='0' && Cr<='9'){Ca=Ca*10+Cr-48;Cr=getchar();}
	return Ca*Cf;
}