#include<bits/stdc++.h>
using namespace std;
typedef long long ll;

ll read() {
    char c=getchar();
    ll ret=0, ne=1;
    while(!('0'<=c&&c<='9')) {
        if(c=='-') ne=-1;
        c=getchar();
    }
    while('0'<=c&&c<='9') {
        ret=ret*10+c-'0';
        c=getchar();
    }
    return ret*ne;
}

char buf[30];
void print(ll x) {
    if(!x) {
        putchar('0'); putchar('\n');
        return ;
    }
    if(x<0) {
        putchar('-'); x=-x;
    }
    int tot=0;
    while(x) {
        buf[++tot]=x%10+'0';
        x/=10;
    }
    for(int i=tot;i>=1;i--) putchar(buf[i]);
    putchar('\n');
}

const int maxn=1e5+5;
const ll M=1e9+7;
void MOD(ll &x) { if(x>=M) x%=M; }

pair<ll,ll> c[maxn];

ll pw(ll x, ll k) {
    if(!k) return 1LL;
    ll p=x;
    --k;
    while(k) {
        if(k&1) x*=p;
        MOD(x);
        p*=p;
        MOD(p);
        k>>=1;
    }
    return x;
}


int main()
{
    freopen("assign.in","r",stdin);
    freopen("assign.out","w",stdout);
    int T=read();
    while(T--) {
        ll n=read(), m=read(), v=read();
        for(int i=1;i<=m;i++) c[i].first=read(), c[i].second=read();
        sort(c+1,c+m+1);
        bool flg=false;
        m=unique(c+1,c+m+1)-c-1;
        for(int i=2;i<=m;i++) {
            if(c[i].first==c[i-1].first) {
                flg=true;
                break;
            }
        }
        if(flg) {
            print(0); continue;
        }
        ll V=v*v%M;
        ll ans=pw(V, c[1].first-1);
        
        for(int i=1;i<m;i++) {
            ans*=(pw(V, c[i+1].first-c[i].first)+M-pw(v, c[i+1].first-c[i].first-1)*(v-1)%M)%M;
            MOD(ans);
        }
        ans*=pw(V, n-c[m].first)%M;
        MOD(ans);
        print(ans);
    }
    
    return 0;
}