#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
	int N, K, Q;
	cin >> N >> K >> Q;
	vector<int> A(N);
	for (int i = 0; i < N; ++i) cin >> A[i];
	int ret = (1 << 30);
	for (int i = 0; i < N; ++i) {
		vector<int> candy, cur;
		for (int j = 0; j <= N; j++) {
			if (j == N || A[j] < A[i]) {
				sort(cur.begin(), cur.end());
				if (cur.size() >= K) candy.insert(candy.end(), cur.begin(), cur.end() - K + 1);
				cur.clear();
			}
			else cur.push_back(A[j]);
		}
		sort(candy.begin(), candy.end());
		if (candy.size() >= Q) ret = min(ret, candy[Q - 1] - A[i]);
	}
	cout << ret << '\n';
	return 0;
}