#include <bits/stdc++.h>
using namespace std;
template <typename T>
void DEBUG(T e) {
  if (true == false) return;
  std::cout << e << " ";
}
template <typename T>
void DEBUG(const std::vector<T> &v) {
  if (true == false) return;
  for (const auto &e : v) {
    std::cout << e << " ";
  }
  std::cout << std::endl;
}
template <typename T>
void DEBUG(const std::vector<std::vector<T>> &vv) {
  if (true == false) return;
  for (const auto &v : vv) {
    DEBUG(v);
  }
}
template <class T, class... Ts>
void DEBUG(T d, Ts... e) {
  if (true == false) return;
  DEBUG(d);
  DEBUG(e...);
}
template <class T>
void corner(bool flg, T hoge) {
  if (flg) {
    cout << hoge << endl;
    abort();
  }
}
template <typename T1, typename T2>
inline bool chmax(T1 &a, T2 b) {
  return a < b && (a = b, true);
}
template <typename T1, typename T2>
inline bool chmin(T1 &a, T2 b) {
  return a > b && (a = b, true);
}
void solve(void) {
  long long n, k, q;
  cin >> n >> k >> q;
  vector<long long> a(n, 0);
  for (long long i = 0; i < n; i++) {
    cin >> a[i];
  }
  long long res = 1223372036854775807LL;
  for (long long i = 0; i < n; i++) {
    vector<long long> p, v;
    for (long long j = 0; j < n; j++) {
      if (a[j] < a[i]) {
        if (v.size() >= k) {
          sort((v).begin(), (v).end());
          for (long long m = 0; m < v.size() - k + 1; m++) {
            p.push_back(v[m]);
          }
          v.clear();
        }
      } else {
        v.push_back(a[j]);
      }
    }
    if (v.size() >= k) {
      sort((v).begin(), (v).end());
      for (long long m = 0; m < v.size() - k + 1; m++) {
        p.push_back(v[m]);
      }
      v.clear();
    }
    if (p.size() < q) continue;
    sort((p).begin(), (p).end());
    chmin(res, p[q - 1] - p[0]);
  }
  cout << res << endl;
  return;
}
int32_t main(int32_t argc, const char *argv[]) {
  std::ios::sync_with_stdio(false);
  std::cin.tie(0);
  std::cout << std::fixed;
  std::cout << std::setprecision(11);
  solve();
  return 0;
}
