#include <bits/stdc++.h>
using namespace std;
int main(int argc, char *argv[]) {
  int n, k, q;
  cin >> n >> k >> q;
  vector<int> a(n);
  for (int i = 0; i < n; ++i) {
    cin >> a[i];
  }
  int ans = 1 << 30;
  for (int i = 0; i < n; ++i) {
    vector<int> x, y;
    for (int j = 0; j <= n; ++j) {
      if (j == n || a[j] < a[i]) {
        if (y.size() >= k) {
          sort(y.begin(), y.end());
          x.insert(x.end(), y.begin(), y.end() - k + 1);
        }
        y.clear();
      } else {
        y.push_back(a[j]);
      }
    }
    if (x.size() < q) {
      break;
    }
    sort(x.begin(), x.end());
    ans = min(ans, x[q - 1] - x[0]);
  }
  cout << ans << endl;
}
