#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N=1e6+5,mod=1e9+7;
int n,m,v,vis[N],ans;
signed main(){
    freopen("assign.in","r",stdin);
    freopen("assign.out","w",stdout);
    int t; cin>>t;
    while(t--){
        memset(vis,0,sizeof(vis)); ans=1; int flag=0;
        scanf("%lld%lld%lld",&n,&m,&v);
        for(int i = 1;i<=m;i++){
            int x,d; scanf("%lld%lld",&x,&d);
            if(vis[x]!=d&&vis[x]!=0){puts("0"); flag=1; break;}
            vis[x]=d; 
        }
        if(flag) continue;
        for(int i = 1;i<n;i++){ 
            if(vis[i]&&vis[i+1]) ans=(ans*(v*(v-1)%mod+1))%mod;
            else ans=(ans*v*v)%mod;
        }                    
        printf("%lld\n",ans);
    }
    return 0;
}