#include<bits/stdc++.h>
#define ll long long
#define pn putchar('\n')
#define fls() fflush(stdout)
#define mset(a,x) memset(a,x,sizeof a)
#define mcpy(a,b) memcpy(a,b,sizeof a)
#define all(a) a.begin(),a.end()
#define int ll
#define mod 1000000007
#define maxn 100005
using namespace std;
int re()
{
    int x=0;
    bool t=1;
    char ch=getchar();
    while(ch<'0'||ch>'9')
    {
        t=ch=='-'?0:t;
        ch=getchar();
    }
    while('0'<=ch&&ch<='9')
    {
        x=(x<<1)+(x<<3)+(ch^48);
        ch=getchar();
    }
    return t?x:-x;
}
int ksm(int x,int y)
{
    int ret=1;
    while(y)
    {
        if(y&1)
            ret=ret*x%mod;
        x=x*x%mod;
        y>>=1;
    }
    return ret;
}
int n,m,k;
pair<int,int>a[maxn];
void solve()
{
    n=re(),m=re(),k=re();
    for(int i=1;i<=m;i++)
        a[i]={re(),re()};
    sort(a+1,a+1+m);
    int ans=ksm(k,a[1].first-1+n-a[m].first<<1);
    for(int i=2;i<=m;i++)
    {
        if(a[i].first==a[i-1].first)
        {
            if(a[i].second!=a[i-1].second)
            {
                puts("0");
                return;
            }
            continue;
        }
        (ans*=ksm(k,a[i].first-a[i-1].first<<1)-ksm(k,a[i].first-a[i-1].first-1)*(k-1)%mod)%=mod;
    }
    if(ans<0)
        ans+=mod;
    printf("%lld\n",ans);
}
signed main()
{
    freopen("assign.in","r",stdin);
    freopen("assign.out","w",stdout);
    int T=re();
    while(T--)
        solve();
}