#include <bits/stdc++.h>
#pragma GCC optimize("O3","unroll-loops")
#pragma GCC target("avx","popcnt","sse4","abm")
using namespace std;
#ifdef MIKU
string dbmc = "\033[1;38;2;57;197;187m", dbrs = "\033[0m";
#define debug(x...) cout << dbmc << "[" << #x << "]: ", dout(x)
void dout() { cout << dbrs << endl; }
template <typename T, typename ...U>
void dout(T t, U ...u) { cout << t << (sizeof...(u) ? ", " : ""); dout(u...); }
#else
#define debug(...) 39
#endif
#define int long long
#define fs first
#define sc second
#define mp make_pair
#define FOR(i, j, k) for (int i = j, Z = k; i < Z; i++)
using ll = long long;
typedef pair<int, int> pii;
const int MXN = 2005, MXC = 1000000005;
int n, X, Y, a[MXN];
int dp[MXN][MXN], l[MXN], l2[MXN];
deque<pii> dq, dq2;
void PRE(int w) {
int p = 0, pp = 0;
FOR(i, 1, n + 1) {
while (a[i] - a[p] >= w) p++;
while (a[i] - a[pp] >= 2 * w) pp++;
l[i] = p - 1;
l2[i] = pp - 1;
}
}
bool check(int w) {
PRE(w);
dp[0][0] = 0;
FOR(j, 1, n + 1) dp[0][j] = dp[0][l2[j]] + 1;
auto POP = [&](deque<pii> &dq, int t) -> void {
while (dq.size() && dq.front().fs < t) dq.pop_front();
};
auto PUSH = [&](deque<pii> &dq, int id, int val) -> void {
while (dq.size() && dq.back().sc >= val) dq.pop_back();
dq.push_back(mp(id, val));
};
FOR(i, 1, X + 1) {
dp[i][0] = 0;
dq.clear();
dq2.clear();
PUSH(dq, 0, 0);
PUSH(dq2, 0, 0);
FOR(j, 1, n + 1) {
POP(dq, l[j]);
POP(dq2, l2[j]);
dp[i][j] = min(dq.front().sc, dq2.front().sc + 1);
PUSH(dq, j, dp[i - 1][j]);
PUSH(dq2, j, dp[i][j]);
}
if (dp[i][n] <= Y) return true;
}
return false;
}
void miku() {
cin >> n >> X >> Y;
FOR(i, 1, n + 1) cin >> a[i];
sort(a + 1, a + n + 1);
n = unique(a + 1, a + n + 1) - (a + 1);
if (X + Y >= n) {
cout << 1 << '\n';
return;
}
a[0] = -2 * MXC;
int l = 0, r = MXC;
while (l + 1 < r) {
int mid = (l + r) >> 1;
(check(mid) ? r : l) = mid;
}
cout << r << '\n';
}
int32_t main() {
cin.tie(0) -> sync_with_stdio(false);
cin.exceptions(cin.failbit);
miku();
return 0;
}
