#include <algorithm>
#include <bitset>
#include <cmath>
#include <complex>
#include <cstring>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <regex>
#include <set>
#include <stack>
#include <string>
#include <vector>

const int MOD = 1e9 + 7;
const int iINF = 2147483647 / 2;
const long long int llINF = 9223372036854775807 / 2;

using namespace std;
using ll = long long int;
using vl = vector<ll>;
using vvl = vector<vector<ll>>;
using vvvl = vector<vector<vector<ll>>>;

typedef pair<ll, ll> pll;
bool paircomp(const pll &a, const pll &b) {
  if (a.first == b.first)
    return a.second < b.second;
  return a.first < b.first;
}

#define REP(i, n) for (ll i = 0; i < (n); i++)
#define RREP(i, n) for (ll i = (n)-1; i >= 0; i--)
#define FOR(i, a, b) for (ll i = (a); i < (b); i++)
#define AUTO(i, m) for (auto &i : m)
#define ALL(a) (a).begin(), (a).end()
#define MAX(vec) *std::max_element(vec.begin(), vec.end())
#define MIN(vec) *std::min_element(vec.begin(), vec.end())
#define ARGMAX(vec)                                                            \
  std::distance(vec.begin(), std::max_element(vec.begin(), vec.end()))
#define ARGMIN(vec)                                                            \
  std::distance(vec.begin(), std::min_element(vec.begin(), vec.end()))
#define REV(T) greater<T>()
#define PQ(T) priority_queue<T, vector<T>, greater<T>>
#define VVL(a, b, c) vector<vector<ll>>(a, vector<ll>(b, c))
#define VV(T, a, b, c) vector<vector<T>>(a, vector<T>(b, c))
#define VVVL(a, b, c, d)                                                       \
  vector<vector<vector<ll>>>(a, vector<vector<ll>>(b, vector<ll>(c, d)))
#define VVV(T, a, b, c, d)                                                     \
  vector<vector<vector<T>>>(a, vector<vector<T>>(b, vector<T>(c, d)))
#define SP(a) setprecision(a)
#define SQRT(a) sqrt((long double)(a))
#define DPOW(a, b) pow((long double)(a), (long double)(b))
#define UNIQUE(vec)                                                            \
  do {                                                                         \
    sort(ALL((vec)));                                                          \
    (vec).erase(std::unique(ALL((vec))), (vec).end());                         \
  } while (0)

ll POW(ll n, ll m) {
  if (m == 0) {
    return 1;
  } else if (m % 2 == 0) {
    ll tmp = POW(n, m / 2);
    return (tmp * tmp);
  } else {
    return (n * POW(n, m - 1));
  }
}

int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  ll N, K, Q;
  cin >> N >> K >> Q;
  vector<ll> A(N);
  REP(i, N) cin >> A[i];
  vector<ll> B = A;
  sort(ALL(B));
  ll ans = llINF;
  REP(i, N) {
    ll x = B[i];
    vvl C(N + 1);
    ll j = 0;
    REP(y, N) {
      if (A[y] >= x)
        C[j].push_back(A[y]);
      else
        j++;
    }
    vl D;
    REP(y, j + 1) {
      sort(ALL(C[y]));
      if (C[y].size() >= K)
        REP(z, C[y].size() - K + 1) D.push_back(C[y][z]);
    }
    if (D.size() >= Q) {
      sort(ALL(D));
      ans = min(ans, D[Q - 1] - D[0]);
    }
  }
  cout << ans << endl;

  return 0;
}
/* うまく行きそうだったけどダメだったやつ(なんでダメかわからん)

  vector<pll> A(N);
  vl B;
  REP(i, N) {
    ll a;
    cin >> a;
    A[i] = make_pair(a, i);
  }
  sort(ALL(A));

  ll ans = A[Q - 1].first - A[0].first;
  REP(i, N - Q) {
    B.push_back(A[i].second);
    ll count = 0;
    ll now = -1;
    sort(ALL(B));
    REP(j, i + 1) {
      count += max(B[j] - now - 1 - K + 1, 0LL);
      // cout << B[j] << "," << B[j] - now - 1 - K + 1 << endl;
      now = B[j];
    }
    // cout << N - now - K << endl;
    count += max(N - now - K, 0LL);
    // cout << count << endl;
    // cout << A[i].second << "," << count << endl;
    if (count < Q) {
      break;
    } else {
      // cout << A[Q + i].first - A[i + 1].first << endl;
      ans = min(ans, A[Q + i].first - A[i + 1].first);
    }
  }
  cout << ans << endl;

 */


Measured memory_bytes: 384