#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <cstdio>
#include <string>
#include <cstdlib>
#include <cmath>
#include <iostream>
#include <cstring>
#include <set>
#include <queue>
#include <algorithm>
#include <vector>
#include <map>
#include <cctype>
#include <cmath>
#include <stack>
#include <sstream>
#include <list>
#include <assert.h>
#include <bitset>
#include <numeric>
#define debug() puts("++++")
#define gcd(a, b) __gcd(a, b)
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define fi first
#define se second
#define pb push_back
#define sqr(x) ((x)*(x))
#define ms(a,b) memset(a, b, sizeof a)
#define sz size()
#define be begin()
#define ed end()
#define pu push_up
#define pd push_down
#define cl clear()
#define lowbit(x) -x&x
//#define all 1,n,1
#define FOR(i,n,x)  for(int i = (x); i < (n); ++i)
#define freopenr freopen("in.in", "r", stdin)
#define freopenw freopen("out.out", "w", stdout)
using namespace std;
 
typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int, int> P;
const int INF = 0x3f3f3f3f;
const LL LNF = 1e17;
const double inf = 1e20;
const double PI = acos(-1.0);
const double eps = 1e-8;
const int maxn = 1e5 + 20;
const int maxm = 1e6 + 10;
const LL mod = 1000000000000000LL;
const int dr[] = {-1, 1, 0, 0, 1, 1, -1, -1};
const int dc[] = {0, 0, 1, -1, 1, -1, 1, -1};
const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"};
int n, m;
const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
inline bool is_in(int r, int c) {
  return r >= 0 && r < n && c >= 0 && c < m;
}
inline int readInt(){ int x;  scanf("%d", &x);  return x; }

char s[52];
int num[1100];

int main(){
  int T;  cin >> T;
  for(int kase = 1; kase <= T; ++kase){
    int K;  scanf("%d %d %d", &n, &m, &K);
    for(int i = 0; i < n; ++i){
      scanf("%s", s);
      num[i] = 0;
      for(int j = 0; j < m; ++j)  num[i] |= (1<<j) * (s[j] - 'A');
    }
    if(K > n * (n-1) / 2){
      printf("Case #%d: 0\n", kase);
      continue;
    }
    int all = 1<<m; 
    int ans = 0;
    vector<int> sub;
    for(int i = all-1; i; --i){
      bool ok = true;
      for(auto &j : sub)  if((j&i) == i){
        ok = false;  break;
      }
      if(!ok)  continue;
      map<int, int> mp;
      for(int j = 0; j < n; ++j)  ++mp[num[j]&i];
      if(mp.sz * ((int)mp.sz-1) >= K * 2) ++ans;
      else{
        int sum = n;
        int cnt = 0;
        for(auto &it : mp){
          cnt += (sum - it.se) * it.se;
          sum -= it.se;
          if(cnt >= K)  break;
        }
        if(cnt >= K)  ++ans;
        else  sub.pb(i);
      }
    }
    printf("Case #%d: %d\n", kase, ans);
  }
  return 0;
}