#include <bits/stdc++.h>
using namespace std;
inline int64_t max(int64_t a, int64_t b) { return (a > b) ? a : b; }
inline int64_t min(int64_t a, int64_t b) { return (a < b) ? a : b; }
inline int64_t max3(int64_t a, int64_t b, int64_t c) {
  return max(a, max(b, c));
}
inline int64_t min3(int64_t a, int64_t b, int64_t c) {
  return min(a, min(b, c));
}
int64_t gcd(int64_t a, int64_t b) { return (a % b == 0) ? b : gcd(b, a % b); }
int64_t pow3(int64_t a, int64_t b, int64_t m = 1000000007) {
  int64_t res = 1;
  while (b > 0) {
    if (b & 1) res = (res * a) % m;
    a = (a * a) % m;
    b >>= 1;
  }
  return res;
}
void solve() {
  int64_t n, p, k;
  cin >> n >> p >> k;
  int64_t a[n];
  for (int64_t i = 0; i < n; i++) cin >> a[i];
  sort(a, a + n);
  int64_t ans = 0;
  int64_t psum = 0;
  for (int64_t i = 0; i < k; i++) {
    int64_t tans = i;
    int64_t tsum = psum;
    if (tsum > p) break;
    for (int64_t j = i + k - 1; j < n; j += k) {
      tsum += a[j];
      if (tsum > p) break;
      tans += k;
    }
    ans = max(ans, tans);
    psum += a[i];
  }
  cout << ans << endl;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int q = 1;
  cin >> q;
  while (q--) {
    solve();
  }
  return 0;
}
