#include <bits/stdc++.h>
using namespace std;
template <class c>
struct rge {
  c b, e;
};
template <class c>
rge<c> range(c i, c j) {
  return rge<c>{i, j};
}
template <class c>
auto dud(c* x) -> decltype(cerr << *x, 0);
template <class c>
char dud(...);
struct debug {
  template <class c>
  debug& operator<<(const c&) {
    return *this;
  }
};
vector<char*> tokenizer(const char* args) {
  char* token = new char[111];
  strcpy(token, args);
  token = strtok(token, ", ");
  vector<char*> v({token});
  while (token = strtok(NULL, ", ")) v.push_back(token);
  return reverse(v.begin(), v.end()), v;
}
void debugg(vector<char*> args) { cerr << "\b\b "; }
template <typename Head, typename... Tail>
void debugg(vector<char*> args, Head H, Tail... T) {
  debug() << " [" << args.back() << ": " << H << "] ";
  args.pop_back();
  debugg(args, T...);
}
long long mod = 1e9 + 7;
const int MX = 0x3f3f3f3f;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n, i, j, k, q, cnt, mi, ma;
  cin >> n >> k >> q;
  int a[n], c[n];
  for (i = 0; i <= n - 1; i++) cin >> a[i], c[i] = a[i];
  sort(c, c + n);
  int ans = c[q - 1] - c[0];
  multiset<int> s;
  for (i = 0; i <= n - k - q; i++) {
    s.clear();
    vector<int> v;
    for (j = 0; j <= n - 1; j++) {
      if (a[j] <= c[i]) {
        if ((int)v.size() >= k)
          for (auto u : v) s.insert(u);
        v.clear();
      } else
        v.emplace_back(a[j]);
    }
    if ((int)v.size() >= k)
      for (auto u : v) s.insert(u);
    if ((int)s.size() < q) break;
    mi = MX;
    ma = 0;
    auto it = s.begin();
    for (j = 1; j <= q; j++) {
      mi = min(mi, *it);
      ma = max(ma, *it);
      it++;
    }
    ans = min(ans, ma - mi);
  }
  cout << ans;
  return 0;
}
