#include <bits/stdc++.h>
using namespace std;
const int INF = 1 << 30;
const int maxn = 2010;
int n, k, q, a[maxn], ans, b[maxn], res[maxn];
int solve(int x) {
  int s = -1, sz = 0;
  for (int i = 1; i <= n + 1; i++)
    if (a[i] >= a[x]) {
      if (s == -1) s = i;
    } else if (s != -1) {
      if (i - s >= k) {
        for (int j = s; j < i; j++) b[j - s + 1] = a[j];
        sort(b + 1, b + (i - s + 1));
        for (int j = 1; j + k - 1 <= i - s; j++) res[++sz] = b[j];
      }
      s = -1;
    }
  if (sz < q) return INF;
  sort(res + 1, res + (sz + 1));
  return res[q] - res[x];
}
int main() {
  scanf("%d %d %d", &n, &k, &q);
  for (int i = 1; i <= n; i++) scanf("%d", &a[i]);
  ans = INF;
  for (int i = 1; i <= n; i++) ans = min(ans, solve(i));
  printf("%d\n", ans);
  return 0;
}
