#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
const long long INF = 1e18;
using P = pair<long long, long long>;
template <typename T>
void chmin(T &a, T b) {
  if (a > b) a = b;
}
template <typename T>
void chmax(T &a, T b) {
  if (a < b) a = b;
}
void pmod(long long &a, long long b) { a = (a + b) % MOD; }
void pmod(long long &a, long long b, long long c) { a = (b + c) % MOD; }
void qmod(long long &a, long long b) { a = (a * b) % MOD; }
void qmod(long long &a, long long b, long long c) { a = (b * c) % MOD; }
long long median(long long a, long long b, long long c) {
  return a + b + c - max({a, b, c}) - min({a, b, c});
}
void ans1(bool x) {
  if (x)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
void ans2(bool x) {
  if (x)
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
}
void ans3(bool x) {
  if (x)
    cout << "Yay!" << endl;
  else
    cout << ":(" << endl;
}
template <typename T1, typename T2>
void ans(bool x, T1 y, T2 z) {
  if (x)
    cout << y << endl;
  else
    cout << z << endl;
}
template <typename T>
void debug(vector<vector<T>> v, long long h, long long w) {
  for (long long i = 0; i < h; i++) {
    cout << v[i][0];
    for (long long j = 1; j < w; j++) cout << " " << v[i][j];
    cout << endl;
  }
};
void debug(vector<string> v, long long h, long long w) {
  for (long long i = 0; i < h; i++) {
    for (long long j = 0; j < w; j++) cout << v[i][j];
    cout << endl;
  }
};
template <typename T>
void debug(vector<T> v, long long n) {
  cout << v[0];
  for (long long i = 1; i < n; i++) cout << " " << v[i];
  cout << endl;
};
template <typename T>
vector<vector<T>> vec(long long x, long long y, T w) {
  vector<vector<T>> v(x, vector<T>(y, w));
  return v;
}
long long gcd(long long x, long long y) {
  long long r;
  while (y != 0 && (r = x % y) != 0) {
    x = y;
    y = r;
  }
  return y == 0 ? x : y;
}
template <typename T>
void emp(map<T, long long> &m, T x) {
  m.emplace(x, 0).first->second++;
}
int main() {
  cin.tie(NULL);
  ios_base::sync_with_stdio(false);
  long long res = 0, res1 = INF, res2 = -INF, buf = 0;
  bool judge = true;
  long long n, k, q;
  cin >> n >> k >> q;
  vector<long long> a(n);
  for (long long i = 0; i < (long long)(n); i++) cin >> a[i];
  auto b = a;
  sort((b).begin(), (b).end());
  b.erase(unique((b).begin(), (b).end()), b.end());
  for (long long i = 0; i < (long long)(b.size()); i++) {
    long long l = 0, r = MOD;
    while (r - l >= 2) {
      long long mid = (l + r) / 2;
      long long cnt1 = 0;
      long long cnt2 = 0;
      long long ret = 0;
      for (long long j = 0; j < (long long)(n); j++) {
        if (a[j] > mid) cnt2++;
        if (a[j] != -1) cnt1++;
        if (a[j] == -1) {
          ret += max(0LL, min(cnt1 - cnt2, cnt1 - k + 1));
          cnt1 = 0;
          cnt2 = 0;
        }
      }
      ret += max(0LL, min(cnt1 - cnt2, cnt1 - k + 1));
      if (ret >= q)
        r = mid;
      else
        l = mid;
    }
    chmax(res, r - b[i]);
    long long cnt = 0, ret = 0;
    for (long long j = 0; j < (long long)(n); j++) {
      if (a[j] == b[i]) {
        ret += cnt - k + 1;
        cnt = 0;
        a[j] = -1;
      } else
        cnt++;
    }
    if (ret < q) break;
  }
  cout << res << endl;
  return 0;
}
