#include<algorithm>
#include<cstdio>
inline int read()
{
    short f=1;int x=0;
    char c=getchar();
    while(c<'0'||c>'9') {if(c=='-')f=-1;c=getchar();}
    while(c>='0'&&c<='9')x=(x<<1)+(x<<3)+(c^48),c=getchar();
    return x*f;
}
typedef long long ll;
const int N=1e5+10,MOD=1e9+7;
int n,m,v;
struct zzn{int x,w;}a[N];
inline int qpow(ll x,int y)
{
	int res=1;
	while(y)
	{
		if(y&1)	res=x*res%MOD;
		x=x*x%MOD;y>>=1;
	}
	return res;
}
inline int sub(const int &x,const int &y){return x-y<0?x-y+MOD:x-y;}
int cnt;
inline void solve()
{
	n=read(),m=read(),v=read();
	for(int i=1;i<=m;i=-~i)	a[i]={read(),read()};
	std::sort(a+1,a+m+1,[&](const zzn &x,const zzn &y){return x.x<y.x;});
	ll ans=qpow(v,a[1].x-1<<1);
	for(int i=1;i<m;i=-~i)
		if(a[i].x==a[i+1].x&&a[i].w!=a[i+1].w)	return void(puts("0"));
		else if(a[i].x!=a[i+1].x)
			ans=ans*sub(qpow(v,a[i+1].x-a[i].x<<1),1ll*qpow(v,a[i+1].x-a[i].x-1)*(v-1)%MOD)%MOD;
	printf("%lld\n",ans*qpow(v,n-a[m].x<<1)%MOD);
}
int main()
{
    freopen("assign.in","r",stdin);
    freopen("assign.out","w",stdout);
	for(int T=read();T;T=~-T)	solve();
    return 0;
}
/*
3
2 1 2
1 1
2 2 2
1 1
2 2
2 2 2
1 1
1 2

4
3
0
*/