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

typedef long long ll;

int read() {
	int n=0,f=1;
	char ch=getchar();
	while(ch<'0' || ch>'9') {
		if(ch=='-') f=-1;
		ch=getchar();
	}
	while(ch>='0' && ch<='9') {
		n=(n<<1)+(n<<3)+ch-'0';
		ch=getchar();
	}
	return f==1?n:-n;
}

void write(ll x) {
	if(x<0) {
		putchar('-');
		x=-x;
	}
	if(x>9) write(x/10);
	putchar((x%10)+'0');
}

const int M=1e5+7;
const ll MOD=1e9+7;

int n,m;
ll v;
struct Opt{
	int id,val;
	friend bool operator <(Opt x,Opt y) {
		return x.id<y.id;
	}
}a[M];

void input() {
	n=read(),m=read(),v=read();
	for(int i=1;i<=m;i++) 
		a[i].id=read(),a[i].val=read();
}

ll qmi(ll a,ll b) {
	ll res=1;
	while(b) {
		if(b&1) res=res*a%MOD;
		a=a*a%MOD;
		b>>=1;
	}
	return res;
}

ll ans;

void work() {
	sort(a+1,a+1+m);
	for(int i=1;i<m;i++) {
		if(a[i].id==a[i+1].id && a[i].val!=a[i+1].val) {
			write(0);
			putchar('\n');
			return;
		}
	}
	ans=1;
	a[0].id=1;
	for(int i=1;i<=m;i++) {
		if(a[i].id==a[i-1].id) continue;
		if(i>=2 && a[i-1].id+1==a[i].id) ans=ans*(v*(v-1)%MOD+1)%MOD;
		else{
			ll mul=qmi(v*v%MOD,a[i].id-a[i-1].id);
			if(i>=2) mul=(mul+MOD-qmi(v,a[i].id-a[i-1].id-1)*(v-1)%MOD)%MOD;
			ans=ans*mul%MOD;
		}
	}
	if(a[m].id!=n) {
		ans=ans*qmi(v*v%MOD,n-a[m].id)%MOD;
	}
	write(ans),putchar('\n');
}

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