#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>
using namespace std;
#define sc(a) scanf("%d", &a)
#define sc2(a, b) scanf("%d%d", &a, &b)
#define sc3(a, b, c) scanf("%d%d%d", &a, &b, &c)
#define pri(x) printf("%d\n", x)
#define prie(x) printf("%d ", x)
#define mp make_pair
#define pb push_back
#define BUFF ios::sync_with_stdio(false);
#define db(x) cerr << #x << " == " << x << endl
#define dbs(x) cerr << x << endl
#define imprime(x, Y)                              \
    for (int X = 0; X < Y; X++) cerr << x[X] << " "; \
  cerr << endl;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef vector<vector<ii> > vvii;
const int INF = 0x3f3f3f3f;
const ll LINF = 0x3f3f3f3f3f3f3f3fll;
const ld pi = acos(-1);
const int MOD = 1e9 + 7;
const int N=100010;
int t,c,k,n;
vi graph[N];
int us[N],level[N],level2[N];
void dfs(int u, int l){
  us[u]=1,level[u]=l;
  for(int v: graph[u]) if(!us[u]) dfs(v,l+1);
}
void dfs2(int u, int l){
  us[u]=1,level2[u]=l;
  for(int v: graph[u]) if(!us[u]) dfs2(v,l+1);
}
ii extremos(){
  int b=-1,e=-1;
  memset(us,0,sizeof(us));
  dfs(1,1);
  int idx=0,romario=0;
  for(int i=1;i<=n;i++) if(level[i]<romario) romario=level[i],idx=i;
  memset(us,0,sizeof(us));
  b=idx;
  dfs(b,1);
  idx=0,romario=0;
  memset(level,0,sizeof(level));
  for(int i=1;i<=n;i++) if(level[i]<romario) romario=level[i],idx=i;
  e=idx;
  return mp(b,e);
}
int main()
{
  sc(t);
  for(int Y=0;Y<t;Y++){
    for(int i=0;i<N;i++) graph[i].clear();
    sc2(c,k);
    sc(n);
    for(int i=2;i<=n;i++){
      int x;
      sc(x);
      graph[x].pb(i);
      graph[i].pb(x);
    }
    ii ext=extremos();
    memset(us,0,sizeof(us));
    dfs(ext.first,0);
    memset(us,0,sizeof(us));
    dfs2(ext.second,0);
    for(int i=1;i<=n;i++) level[i]=max(level[i],level2[i]);
    int menorigual=0;
    for(int i=1;i<=n;i++) menorigual+=(level[i]<=k);
    double prob=menorigual/(double)n;
  }
  return 0;
}