#include <vector> 
#include <list> 
#include <map> 
#include <set> 
#include <deque> 
#include <queue> 
#include <stack> 
#include <bitset> 
#include <algorithm> 
#include <functional> 
#include <numeric> 
#include <utility> 
#include <sstream> 
#include <iostream> 
#include <iomanip> 
#include <cstdio> 
#include <cmath> 
#include <cstdlib> 
#include <cctype> 
#include <string> 
#include <cstring> 
#include <ctime> 

using namespace std;

#define _int64 long long

vector<pair<int,int> > a;
vector<int> ind;
vector<int> d[110000];
double aa[110000];
double ans;
map<int,int> mp;
map<int,int> ind1;

int main()
{
  double tmp,tmp1;
  int i,j,k,m,n,x,y,ll,rr,l,t;
  scanf("%d",&t);
  for (l=0;l<t;l++)
  {
    scanf("%d%d%d",&n,&m,&k);
    ind.clear();
    a.clear();
    ind1.clear();
    for (i=0;i<n;i++)
    {
      scanf("%d%d",&x,&y);
      a.push_back(make_pair(x,y));
      ind.push_back(x);
      ind1[x]=i;
    }
    sort(a.begin(),a.end());
    mp.clear();
    for (i=0;i<n;i++)
    {
      mp[a[i].first]=i;
      aa[i]=a[i].second;
      d[i].clear();
      ll=i-1;rr=i+1;
      d[i].clear();
      for (j=0;j<k;j++)
      {
        if ((ll<0)||
            ((rr<n)&&
                ((a[rr].first-a[i].first<a[i].first-a[ll].first)||((a[rr].first-a[i].first==a[i].first-a[ll].first)&&(ind1[a[rr].first]<ind1[a[ll].first])))))
        {
          d[i].push_back(rr);
          rr++;
        }
        else
        {
          d[i].push_back(ll);
          ll--;
        }
      }
    }
    ans=0;
    tmp1=1.0/k;
    for (i=0;i<m;i++)
    {
      scanf("%d",&x);
      x--;
      x=mp[ind[x]];
      tmp=0;
      for (j=0;j<d[x].size();j++)
        tmp+=aa[d[x][j]];
      tmp*=tmp1;
      aa[x]=tmp;
      ans+=tmp;
    }
    printf("%.6lf\n",ans);
  }
}