#include <bits/stdc++.h>
using namespace std;
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { os << '{'; string sep; for (const T &x : v) os << sep << x, sep = ", "; return os << '}'; }
#define ll long long
#define ld long double
#define all(a) (a).begin(), (a).end()
#define sui cout.tie(NULL); cin.tie(NULL); ios_base::sync_with_stdio(false)
const int MAX_N = 2e3 + 5;
const int MOD = 1e9 + 7;
const ll INF = 1e9;
const ld EPS = 1e-9;
const int LOG = 30;
int n, p, q;
int a[MAX_N];
bool check(int x)
{
int dp[n + 1][q + 1];
for (int i = 0; i <= q; i++) dp[n][i] = 0;
int last1 = n;
int last2 = n;
for (int i = n - 1; i >= 0; i--)
{
while (a[last1 - 1] - a[i] >= x) last1--;
while (a[last2 - 1] - a[i] >= 2 * x) last2--;
for (int j = 0; j <= q; j++)
{
dp[i][j] = 1 + dp[last1][j];
if (j) dp[i][j] = min(dp[i][j], dp[last2][j - 1]);
}
}
if (dp[0][q] <= p) return true;
return false;
}
void solve() {
cin >> n >> p >> q;
for (int i = 0; i < n; i++) cin >> a[i];
sort(a, a + n);
if (p + q >= n)
{
cout << 1 << "\n";
return;
}
int l = 0;
int r = INF;
while (r - l > 1)
{
int mid = (r + l) >> 1;
if (check(mid)) r = mid;
else l = mid;
}
cout << r << "\n";
}
int main() {
sui;
int tc = 1;
//cin >> tc;
for (int t = 1; t <= tc; t++) {
solve();
}
}
