#include<cstdio>
#include<algorithm>
typedef long long ll;
inline void read(int&x){
	x=0;
	char c=getchar();
	bool f=0;
	for(;c<'0'||c>'9';c=getchar())if(c=='-')f=1;
	for(;c>='0'&&c<='9';c=getchar())x=x*10+(c^48);
	if(f)x=-x;
}
const int N=100005,mod=1000000007;
int T,n,m,v,val[N],ans;
struct Node{
	int c,d;
	bool operator<(const Node&y){
		return c<y.c;
	}
}a[N];
inline int mul(int x,int y){
	return ll(x)*y%mod;
}
inline void Mul(int&x,int y){
	x=ll(x)*y%mod;
}
inline int pow(int x,int y){
	x%=mod;
	int res=1;
	for(;y;Mul(x,x),y>>=1)if(y&1)Mul(res,x);
	return res;
}
inline int fix(int x){
	return x+((x>>31)&mod);
}
inline int sub(int x,int y){
	return fix(x-y);
}
inline int sqr(int x){
	return ll(x)*x%mod;
}
void work(){
	read(n),read(m),read(v),ans=1;
	for(int i=1;i<=m;i++)read(a[i].c),read(a[i].d);
	std::sort(a+1,a+m+1);
	Mul(ans,pow(sqr(v),a[1].c-1)),Mul(ans,pow(sqr(v),n-a[m].c));
	for(int i=1;i<m;i++){
		if(a[i].c!=a[i+1].c)Mul(ans,sub(pow(sqr(v),a[i+1].c-a[i].c),mul(v-1,pow(v,a[i+1].c-a[i].c-1))));
		else if(a[i].d!=a[i+1].d){
			puts("0");
			return;
		}
	}
	printf("%d\n",ans);
}
int main(){
	freopen("assign.in","r",stdin),freopen("assign.out","w",stdout);
	for(read(T);T--;)work();
	return fflush(stdout),fclose(stdin),fclose(stdout),0;
}
//a;