#include<bits/stdc++.h>
#define rep(i,j,k) for(int i=j;i<=k;i++)
#define repp(i,j,k) for(int i=j;i>=k;i--)
#define pii pair<int,int>
#define mp make_pair
#define fir first
#define sec second
#define ls(x) (x<<1)
#define rs(x) ((x<<1)|1)
#define lowbit(i) (i&-i)
#define int long long
using namespace std;
typedef long long ll;
const int N=1e5+5,mo=1e9+7;
void read(int &p){
    int x=0,w=1;
    char ch=getchar();
    while(!isdigit(ch)){
        if(ch=='-')w=-1;
        ch=getchar();
    }
    while(isdigit(ch)){
        x=(x<<3)+(x<<1)+ch-'0';
        ch=getchar();
    }
    p=x*w;
}
int T;
int n,m,v;
pii lim[N];
int quick_power(int base,int x){
    int res=1;
    while(x){
        if(x&1)res*=base,res%=mo;
        base*=base,base%=mo;
        x>>=1;
    }
    return res;
}
void solve(){
    read(n),read(m),read(v);
    rep(i,1,m)
        read(lim[i].fir),read(lim[i].sec);
    sort(lim+1,lim+m+1);
    rep(i,2,m){
        if(lim[i].fir==lim[i-1].fir&&lim[i].sec!=lim[i-1].sec){
            puts("0");
            return;
        }
    }
    int ans=quick_power(v,2ll*(lim[1].fir-1));
    rep(i,2,m){
        if(lim[i].fir==lim[i-1].fir)continue;
        int dis=lim[i].fir-lim[i-1].fir-1,res=quick_power(v,2*(dis+1));
        res=res+mo-quick_power(v,dis)*(v-1)%mo,res%=mo;
        ans*=res,ans%=mo;
    }
    ans*=quick_power(v,2ll*(n-lim[m].fir)),ans%=mo;
    printf("%lld\n",ans);
}
signed main(){
    freopen("assign.in","r",stdin);
    freopen("assign.out","w",stdout);
    read(T);
    while(T--)
        solve();
    return 0;
}
//passed on 9.16.good luck!