#include<bits/stdc++.h>

#define N 100005
#define M 1000000007

using namespace std;

struct pint{
    int c,d;
    friend bool operator<(const pint& l,const pint& r){
        return l.c<r.c;
    }
};

long long fpow(long long a,long long b){//a^b
    long long ans=1;
    while(b){
        if(b&1)
            ans=(ans*a)%M;
        a=(a*a)%M;
        b>>=1;
    }
    return ans;
}

int T,n,m,v;
pint ar[N];

int main(){
    //cout << fpow(86*85+1,502);
    //cout << fpow(3,-1);
    //return 0;
    freopen("assign.in","r",stdin);
    freopen("assign.out","w",stdout);
    cin >> T;
    while(T--){
        cin >> n >> m >> v;
        for(int i=0;i<m;i++){
            cin >> ar[i].c >> ar[i].d;
        }
        sort(ar,ar+m);
        int flag=1;
        for(int i=0;i<m&&flag;){
            int t,c0=ar[i].c;
            for(t=i;i<m&&ar[i].c==ar[t].c&&flag;i++){
                if(ar[i].d!=ar[t].d)
                    flag=0;
            }
        }
        //cout << n << ' ' << m << ' ' << v << ':';
        if(flag==0){
            cout << 0 << endl;
            continue;
        }

        long long ans=1;
        ans=(ans*fpow(v,2*(ar[0].c-1)))%M;
        //cout << fpow(v,2*(ar[0].c-1)) << ' ';
        int j;
        for(int i=0;i<m-1;i=j){
            j=i;
            while(ar[j].c==ar[i].c&&j<m-1) j++;
            //cout << j << ' ';
            //cout << 2*(ar[j].c-ar[i].c) << ' ' << ar[j].c-ar[i].c-1 << endl;
            if(j==m-1&&ar[i].c==ar[j].c)
                break;
            long long v1=fpow(v,ar[j].c-ar[i].c);
            long long v2=fpow(v,ar[j].c-ar[i].c-1);
            //cout << v2 << ' ' << v1 << ' ' << (v2-v1*(v-1)) << endl;
            if(v1-1<0)
                ans=(ans*(((v1*(v1-1+M))%M+v2)%M))%M;
            else
                ans=(ans*(((v1*(v1-1))%M+v2)%M))%M;
        }
        ans=(ans*fpow(v,2*(n-ar[m-1].c)))%M;
        //cout << fpow(v,2*(n-ar[m-1].c)) << endl;
        cout << ans << endl;
    }
    fclose(stdin);
    fclose(stdout);
    return 0;
}
/*

10 11 2
2 2
3 2
4 2
7 2
10 2
*/