#include<bits/stdc++.h>
using namespace std;
const int M=100009, MOD=1000000007;
int T,n,m,v;
pair<int,int> c[M];
int read() {
	char c; int res=0;
	do { c=getchar(); } while (c<'0' || c>'9');
	do { res=res*10+c-'0'; c=getchar(); } while (c>='0' && c<='9');
	return res;
}
long long qpow(long long a,int b) {
	long long ans=1;
	while (b) {
		if (b&1) ans=ans*a%MOD;
		a=a*a%MOD; b>>=1;
	}
	return ans;
}
void solve() {
	n=read(); m=read(); v=read();
	for (int i=1;i<=m;i++) { c[i].first=read(); c[i].second=read(); }
	sort(c+1,c+m+1);
	m=unique(c+1,c+m+1)-(c+1);
	//printf("%d\n",m);
	//for (int i=1;i<=m;i++) printf("%d %d\n",c[i].first,c[i].second);
	for (int i=1;i<m;i++)
		if (c[i].first==c[i+1].first) {
			printf("0\n");
			return;
		}
	int ans=1, v2=1LL*v*v%MOD;
	for (int i=1;i<m;i++) {
		int d=c[i+1].first-c[i].first;
		long long rec1=qpow(v2,d);
		long long rec2=qpow(v,d-1)*(v-1)%MOD;
		ans=ans*(rec1-rec2+MOD)%MOD;
	}
	ans=ans*qpow(v2,c[1].first-1)%MOD;
	ans=ans*qpow(v2,n-c[m].first)%MOD;
	printf("%d\n",ans);
}
int main() {
	freopen("assign.in","r",stdin);
	freopen("assign.out","w",stdout);
	T=read();
	while (T--) solve();
	return 0;
}