#define Plus_Cat "assign"
#include<bits/stdc++.h>
#define INF 0x3f3f3f3f
#define ll long long
#define RCL(a,b,c,d) memset(a,b,sizeof(c)*(d))
#define tomin(a,...) ((a)=min({(a),__VA_ARGS__}))
#define tomax(a,...) ((a)=max({(a),__VA_ARGS__}))
#define FOR(i,a,b) for(int i(a); i<=(int)(b); ++i)
#define DOR(i,a,b) for(int i(a); i>=(int)(b); --i)
#define EDGE(g,i,x,y) for(int i(g.h[x]),y(g[i].v); ~i; y=g[i=g[i].nxt].v)
using namespace std;
constexpr int N(1e9+10),M(1e5+10);

namespace IOEcat {
#define isD(c) ('0'<=(c)&&(c)<='9')
#define DE(...) E(#__VA_ARGS__,__VA_ARGS__)
	struct Icat {

		char getc() {
			return getchar();
		}

		template<class T>void operator ()(T &x) {
			static bool sign(0);
			static char ch(0);
			sign=0,x=0;
			while(ch=getc(),!isD(ch))if(ch=='-')sign=1;
			do x=(x<<1)+(x<<3)+(ch^48);
			while(ch=getc(),isD(ch));
			if(sign)x=-x;
		}

		template<class T,class...Types>void operator ()(T &x,Types&...args) {
			return (*this)(x),(*this)(args...);
		}

	} I;
	struct Ocat {

		void putc(char c) {
			putchar(c);
		}

		template<class T>void operator ()(T x,const char lst='\n') {
			static int top(0);
			static char st[50];
			if(x<0)x=-x,putc('-');
			do st[++top]=(x%10)^48,x/=10;
			while(x);
			while(top)putc(st[top--]);
			putc(lst);
		}

		template<class T,class...Types>void operator ()(T x,const char lst='\n',Types...args) {
			return (*this)(x,lst),(*this)(args...);
		}

	} O;
	struct Ecat {

		template<class T>void operator ()(const char *fmt,const T x) {
			cerr<<fmt<<":"<<x<<"."<<endl;
		}

		template<class T,class...Types>void operator ()(const char *fmt,const T x,const Types...args) {
			while(*fmt^',')cerr<<*fmt++;
			return cerr<<':'<<x<<" ,",(*this)(++fmt,args...);
		}

	} E;

} using namespace IOEcat;

namespace Modular {
#define Mod 1000000007

	template<class T1,class T2>constexpr auto add(T1 a,T2 b) {
		return a+b>=Mod?a+b-Mod:a+b;
	}

	template<class T1,class T2>T1 &toadd(T1 &a,T2 b) {
		return a=add(a,b);
	}

	template<class T1,class T2>constexpr auto mul(T1 a,T2 b) {
		return (ll)a*b%Mod;
	}

	template<class T1,class T2>T1 &tomul(T1 &a,T2 b) {
		return a=mul(a,b);
	}

	int Pow(int a,int b=Mod-2) {
		int res(1);
		for(a%=Mod; b; b>>=1,tomul(a,a))if(b&1)tomul(res,a);
		return res;
	}

} using namespace Modular;

int Cas,n,m,v,ans;
struct node {
	int c,d;

	friend bool operator <(node a,node b) {
		return a.c<b.c;
	}

} a[M];

int Cmain() {
	/*Input*/
	I(n,m,v),ans=1;
	FOR(i,1,m)I(a[i].c,a[i].d);
	sort(a+1,a+m+1);
	FOR(i,1,m-1)if(a[i].c==a[i+1].c&&a[i].d!=a[i+1].d)return puts("0"),0;
	if(a[1].c>1)tomul(ans,Pow(v,2*(a[1].c-1)));
	FOR(i,1,m-1)if(a[i].c!=a[i+1].c) {
		int val(add(
			Pow(v,2*(a[i+1].c-a[i].c)),
			Mod-mul(v-1,Pow(v,a[i+1].c-a[i].c-1))
		));
		tomul(ans,val);
	}
	if(a[m].c<n)tomul(ans,Pow(v,2*(n-a[m].c)));
	O(ans,'\n');
	return 0;
}

int main() {
#ifdef Plus_Cat
	freopen(Plus_Cat ".in","r",stdin),freopen(Plus_Cat ".out","w",stdout);
#endif
	for(I(Cas); Cas; --Cas)Cmain();
	return 0;
}