#include <iostream>
#include <cstdio>
#include <queue>
#include <algorithm>
using namespace std;
int ans;
int n, k, q, a[2010], ls[2010];
priority_queue <int, vector <int>, greater <int> > q1, q2;
int main () {
	scanf ("%d%d%d", &n, &k, &q);
	for (int i = 1; i <= n; i++) scanf ("%d", &a[i]), ls[i] = a[i];
	sort (ls + 1, ls + n + 1);
	ans = ls[n] - ls[1];
	for (int p = 1; p <= n; p++) {
		for (int i = 1; i <= n; i++) if (a[i] >= ls[p]) {
			int j = i; while (j < n && a[j + 1] >= ls[p]) j++;
			if (j - i + 1 < k) { i = j; continue; }
			for (int x = i; x <= j; x++) q1.push (a[x]);
			for (int x = j - i + 1; x >= k; x--) q2.push (q1.top ()), q1.pop ();
			while (!q1.empty ()) q1.pop ();
			i = j;
		}
		int mx = 0; bool ok = true;
		for (int i = 1; i <= q; i++) {
			if (q2.empty ()) { ok = false; break; }
			mx = q2.top (), q2.pop ();
		}
		if (ok) ans = min (ans, mx - ls[p]);
	}
	printf ("%d\n", ans);
	return 0;
}