#include<iostream>
#include<algorithm>

using namespace std;

const int N = 2005;
int n, k, q, a[N], ans = 1e9 + 5, t[N], b[N], c[N];

void cal(int mn) {
	int l = 1, r = 1;
	b[0] = 0;
	while (l <= n) {
		c[0] = 0;
		while (a[l] < mn && l <= n)  l++;
		r = l;
		while (a[r] >= mn && r <= n) r++;
		for (int i = l; i < r && i <= n; i++)
			c[++c[0]] = a[i];
		if (c[0] >= k) {
			sort(c + 1, c + c[0] + 1);
			for (int i = 1; i <= c[0] - k + 1; i++)
				b[++b[0]] = c[i];
		}
		l = r;
	}
	sort(b + 1, b + b[0] + 1);
	if (b[0] >= q)   ans = min(ans, b[q] - b[1]);
}

int main() {
	cin >> n >> k >> q;
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
		t[i] = a[i];
	}
	sort(t + 1, t + n + 1);
	for (int i = 1; i <= n; i++)
		cal(t[i]);
	cout << ans << endl;
	return 0;
}