#include <vector>
#include <iostream>
#include <cmath>
#include <map>
#include <unordered_map>
#include <algorithm>
#include <fstream>
#include <unistd.h>
#include <string>
#include <numeric>
#include <queue>
#include <deque>
#include <sstream>
#include <iomanip>
#include <set>
#include <stack>
#include <cassert>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<vvl> vvvl;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<bool> vb;
typedef vector<vector<bool>> vvb;
typedef vector<vvb> vvvb;
typedef vector<vvvb> vvvvb;
typedef vector<string> vs;
typedef vector<vs> vvs;
typedef vector<vvs> vvvs;
typedef vector<char> vc;
typedef vector<vector<char>> vvc;
typedef vector<double> vd;
typedef vector<vd> vvd;
typedef vector<vvd> vvvd;
typedef pair<ll, ll> PL;
typedef vector<PL> vpl;
typedef vector<vector<PL>> vvpl;
const int INF = 1001001001;
const ll LINF = 1e17;
const double pi = 3.1415926535897932;
const string endstr = "\n";
#define FOR(i, a, b) for(ll i = (a); i < b; i++)
#define RFOR(i, a, b) for(ll i = (a); i > b; i--)
#define rep(i, n) for(ll i = 0; i < n; i++)
#define rrep(i, n) for(ll i = n-1; i > -1; i--)
#define FORMAP(it, m) for(auto it = m.begin(); it != m.end(); it++)
#define ff first
#define ss second
#define pb push_back
#define epb emplace_back

template <typename T>
T gcd(T a, T b) {
    return (a == 0) ? b : gcd(b%a, a);
}
template <typename T>
T lcm(T a, T b) {
    return a / gcd(a, b) * b;
}

bool p_comp_fs(const PL p1, const PL p2){ return p1.first < p2.first;};
bool p_comp_fg(const PL p1, const PL p2){ return p1.first > p2.first;};
bool p_comp_ss(const PL p1, const PL p2){ return p1.second < p2.second;};
bool p_comp_sg(const PL p1, const PL p2){ return p1.second > p2.second;};
template <typename T>
vector<T> uniquen(vector<T> vec){
    vec.erase(unique(vec.begin(), vec.end()), vec.end());
    return vec;
}

inline ll popcnt(ll x){return __builtin_popcount((unsigned int)x);};
template<class T> bool chmax(T &a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> bool chmin(T &a, T b) { if (a > b) { a = b; return true; } return false; }

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    ll N, K, Q; cin >> N >> K >> Q;
    vl A(N); vpl X(N);
    rep(i, N){
        cin >> A[i];
        X[i] = {A[i], i};
    }
    sort(X.begin(), X.end());
    
    ll ans = LINF; set<ll> ter; ter.insert(N);
    rep(idx, N){
        priority_queue<ll, vl, greater<ll>> pq;
        ll l = 0;
        for(auto r : ter)
        {
            if(r - l < K){
                l = r+1; continue;
            }
            priority_queue<ll, vl, greater<ll>> pq_tmp;
            FOR(m, l, r) pq_tmp.push(A[m]);
            rep(m, r-l-K+1){
                pq.push(pq_tmp.top()); pq_tmp.pop();
            }
            l = r+1;
        }
        if(pq.size() < Q) break;
        else{
            ll mx = 0, mn = LINF;
            rep(i, Q){
                chmax(mx, pq.top()); chmin(mn, pq.top());
                pq.pop();
            }
            chmin(ans, mx-mn);
        }
        ter.insert(X[idx].ss);
    }
    cout << ans << endstr;
    return 0;
}


Measured memory_bytes: 384