#include<bits/stdc++.h>
#define up(i,l,r) for(int i=(l);i<=(r);++i)
#define down(i,l,r) for(int i=(l);i>=(r);--i)
#define pi pair<int,int>
#define p1 first
#define p2 second
#define m_p make_pair
#define p_b push_back
typedef long long ll;
using namespace std;
const int maxn=1e5+10,mod=1e9+7;
inline ll read(){
    ll x=0;short t=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')t=-1;ch=getchar();}
    while(ch>='0'&&ch<='9')x=x*10+ch-'0',ch=getchar();
    return x*t;
}
int n,m,v;
int qp(int a,int b){
    int res=1;
    while(b){
        if(b&1)res=res*1ll*a%mod;
        a=a*1ll*a%mod;b>>=1;
    }return res;
}
void slv(){
    n=read(),m=read(),v=read();
    vector<pi>A,B;
    up(i,1,m){
        int x=read(),y=read();
        A.p_b(m_p(x,y));
    }
    sort(A.begin(),A.end());
    for(auto it:A)if(B.empty())B.p_b(it);else if(it!=B.back())B.p_b(it);
    A=B;int sz=A.size();
    up(i,0,sz-2)if(A[i].p1==A[i+1].p1){printf("0\n");return;}
    vector<int>P;for(auto it:A)P.p_b(it.p1);
    int res=qp(v,2*(P[0]-1));sz=P.size();
    up(i,1,sz-1){
        int L=P[i]-P[i-1];
        int val=qp(v,L-1);
        res=res*1ll*((val*1ll*val%mod*1ll*v%mod*1ll*v%mod-val*1ll*(v-1)%mod+mod)%mod)%mod;
    }res=res*1ll*qp(v,2*(n-P[sz-1]))%mod;
    printf("%d\n",res);
}int main(){
    freopen("assign.in","r",stdin);
    freopen("assign.out","w",stdout);
    int t=read();while(t--)slv();
    fclose(stdin);
    fclose(stdout);
    return 0;
}