#include "bits/stdc++.h"

using namespace std;

#define DEBUG(x) cout<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cout<<#v<<":";for(int i=0;i<v.size();i++) cout<<" "<<v[i]; cout<<endl

typedef long long ll;
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
#define fi first
#define se second
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
const ll inf = 1000000001;
const ll INF = 2e18;
const ll MOD = 1000000007;
//const ll mod = 1000000009;
const double pi = 3.14159265358979323846;
#define Sp(p) cout<<setprecision(15)<< fixed<<p<<endl;
int dx[4] = { 1,0, -1,0 }, dy[4] = { 0,1,0,-1 };
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
#define fio() cin.tie(0); ios::sync_with_stdio(false);


class LazySegmentTree {
public:
	int n;
	vector<pii> node, lazy;

	LazySegmentTree(vector<pii> a) {
		int _n = a.size();
		n = 1; while (n < _n) n *= 2;
		node.resize(2 * n - 1);
		lazy.resize(2 * n - 1, pii(-2 * inf, -2 * inf));
		for (int i = 0; i < _n; i++) node[i + n - 1] = a[i];
		for (int i = n - 2; i >= 0; i--) {
			node[i].first = node[i * 2 + 1].first + node[i * 2 + 2].first;
			node[i].second = node[i * 2 + 1].second + node[i * 2 + 2].second;
		}
	}

	// k番目のノードについて遅延評価を行う
	inline void eval(int k, int l, int r) {
		if (lazy[k].first != -2 * inf) {
			node[k].first = (r - l) * lazy[k].first;
			node[k].second = (r - l) * lazy[k].second;
			if (r - l > 1) {
				lazy[2 * k + 1] = lazy[k]; /////
				lazy[2 * k + 2] = lazy[k]; /////
			}
			lazy[k] = pii(-2 * inf, -2 * inf);
		}
	}

	// [a, b)をxにする
	void add(int a, int b, pii x, int k, int l, int r) {
		// k 番目のノードに対して遅延評価を行う
		eval(k, l, r);
		if (b <= l || r <= a) return;
		if (a <= l && r <= b) {
			lazy[k] = x;
			eval(k, l, r);
		}
		else {
			add(a, b, x, 2 * k + 1, l, (l + r) / 2);
			add(a, b, x, 2 * k + 2, (l + r) / 2, r);
			node[k].first = node[2 * k + 1].first + node[2 * k + 2].first;
			node[k].second = node[2 * k + 1].second + node[2 * k + 2].second;
		}
	}

	pii getsum(int a, int b, int k, int l, int r) {
		eval(k, l, r);
		if (b <= l || r <= a) return pii(0, 0);
		if (a <= l && r <= b) return node[k];
		pii resl = getsum(a, b, 2 * k + 1, l, (l + r) / 2);
		pii resr = getsum(a, b, 2 * k + 2, (l + r) / 2, r);
		return pii(resl.first + resr.first, resl.second + resr.second);
	}
};

class Bit {
public:
	int n;
	vl bit; // 1-index

	Bit(int _n) { n = _n; bit.resize(n); }


	// [1, i]の和
	// [0, i)の和
	ll sum(int i) {
		ll s = 0;
		while (i > 0) {
			s += bit[i - 1];
			i -= i & -i;
		}
		return s;
	}

	//iは1-index
	void add(int i, ll x) {
		i++;
		while (i <= n) {
			bit[i - 1] += x;
			i += i & -i;
		}
	}

	// bitに入ってる中でx番目に小さい数を求める
	// 1番小さい数はx = 1;
	// bitに3を入れる→add(3, 1), 3を出す→add(3, -1)
	ll min_xth(int x) {
		int left = 0, right = 200000;
		while (left + 1 < right) {
			int mid = (left + right) / 2;
			int temp = sum(mid);
			if (temp < x) {
				left = mid;
			}
			else {
				right = mid;
			}
		}
		return right;
	}

};


int main() {
	int n, k, q;
	cin >> n >> k >> q;
	vi a(n);
	rep(i, n) {
		cin >> a[i];
	}
	vector<pii> ai(n);
	rep(i, n) {
		ai[i].first = a[i]; ai[i].second = i;
	}
	sort(ai.begin(), ai.end());
	vi idx(n);
	rep(i, n) {
		idx[i] = ai[i].second;
	}
	vector<bool> used(n);
	vector<pii> b(n, pii(-1, n));
	int ans = inf;
	rep(i, n) {
		LazySegmentTree lst(b);
		Bit bit(n);
		rep(j, i) {
			used[idx[j]] = true;
			pii now = lst.getsum(idx[j], idx[j] + 1, 0, 0, lst.n);
			lst.add(now.first + 1, idx[j], pii(now.first, idx[j]), 0, 0, lst.n);
			lst.add(idx[j] + 1, now.second, pii(idx[j], now.second), 0, 0, lst.n);
		}
		int cnt = 0;
		int j = i;
		int mi = inf;
		int ma = 0;
		while (cnt < q && j < n) {
			//DEBUG(j);
			//DEBUG(idx[j]);
			//DEBUG(cnt);
			pii now = lst.getsum(idx[j], idx[j] + 1, 0, 0, lst.n);
			int num = bit.sum(now.second) - bit.sum(now.first);
			if (now.second - now.first - 1 - num < k) {
				used[idx[j]] = true;
				lst.add(now.first + 1, idx[j], pii(now.first, idx[j]), 0, 0, lst.n);
				lst.add(idx[j] + 1, now.second, pii(idx[j], now.second), 0, 0, lst.n);
				j++;
				continue;
			}
			mi = min(mi, a[idx[j]]);
			ma = max(ma, a[idx[j]]);
			cnt++;
			bit.add(idx[j], 1);
			j++;
		}
		//DEBUG(cnt);
		if (cnt < q) {
			break;
		}
		else {
			ans = min(ma - mi, ans);
		}
	}
	cout << ans << endl;
}

Measured memory_bytes: 384