#include <bits/stdc++.h>
using namespace std;
int read(){
    int xx=0,ff=1;
    char ch=getchar();
    while(ch<'0' or ch>'9'){
        if(ch=='-') ff=-1;
        ch=getchar();
    }
    while(ch>='0' and ch<='9'){
        xx=(xx<<1)+(xx<<3)+(ch^48);
        ch=getchar();
    }
    return xx*ff;
}
void write(int xx){
    if(xx<0){
        putchar('-');
        xx=-xx;
    }
    if(xx>9) write(xx/10);
    putchar(xx%10+'0');
}
const int M=1e5,mod=1e9+7;
int jin(int A,int B){return A-B<0?A-B+mod:A-B;}
int qp(int A,int B){
    int res=1;
    while(B){
        if(B&1) res=1ll*res*A%mod;
        A=1ll*A*A%mod;
        B>>=1;
    }
    return res;
}
int T,n,m,v,v2;
pair<int,int> a[M+10];
void solve(){
    n=read(); m=read(); v=read();
    v2=1ll*v*v%mod;
    for(int i=1;i<=m;++i){
        a[i].first=read();
        a[i].second=read();
    }
    sort(a+1,a+m+1);
    m=unique(a+1,a+m+1)-a-1;
    for(int i=1;i<m;++i){
        if(a[i].first==a[i+1].first){
            cout << "0\n";
            return;
        }
    }
    int ans=1ll*qp(v2,a[1].first-1)*qp(v2,n-a[m].first)%mod;
    for(int i=2;i<=m;++i){
        int lp=a[i].first-a[i-1].first;
        ans=1ll*ans*jin(qp(v2,lp),1ll*qp(v,lp-1)*(v-1)%mod)%mod;
    }
    write(ans); putchar('\n');
}
int main() {
    freopen("assign.in","r",stdin);
    freopen("assign.out","w",stdout);
    T=read();
    while(T--){
        solve();
    }
    return 0;
}

/*
g++ assign.cpp -o assign -O2 -std=c++14 -Wall -Wextra -Wshadow -Wconversion -fsanitize=address -fsanitize=undefined
*/