/*
* Author: Nonoze
* Created: Tuesday 16/12/2025
*/
#include <bits/stdc++.h>
using namespace std;
#ifndef DEBUG
#define dbg(...)
#endif
// #define cout cerr << "OUT: "
#define endl '\n'
#define endlfl '\n' << flush
#define quit(x) return (void)(cout << x << endl)
template<typename T> void read(T& x) { cin >> x; }
template<typename T1, typename T2> void read(pair<T1, T2>& p) { read(p.first), read(p.second); }
template<typename T> void read(vector<T>& v) { for (auto& x : v) read(x); }
template<typename T1, typename T2> void read(T1& x, T2& y) { read(x), read(y); }
template<typename T1, typename T2, typename T3> void read(T1& x, T2& y, T3& z) { read(x), read(y), read(z); }
template<typename T1, typename T2, typename T3, typename T4> void read(T1& x, T2& y, T3& z, T4& zz) { read(x), read(y), read(z), read(zz); }
template<typename T> void print(vector<T>& v) { for (auto& x : v) cout << x << ' '; cout << endl; }
#define sz(x) (int)(x.size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define make_unique(v) sort(all(v)), v.erase(unique(all(v)), (v).end())
#define pb push_back
#define mp(a, b) make_pair(a, b)
#define fi first
#define se second
#define cmin(a, b) a = min(a, b)
#define cmax(a, b) a = max(a, b)
#define YES cout << "YES" << endl
#define NO cout << "NO" << endl
#define QYES quit("YES")
#define QNO quit("NO")
#define int long long
#define double long double
const int inf = numeric_limits<int>::max() / 4;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int MOD = 1e9+7, LOG=20;
void solve();
signed main() {
ios::sync_with_stdio(0);
cin.tie(0);
int tt=1;
// cin >> tt;
while(tt--) solve();
return 0;
}
int n, x, y;
vector<int> a, nxt1, nxt2;
vector<vector<short>> memo;
int cur;
int dp(int pos, int nbtwo) {
if (pos>=n) return 0;
if (memo[pos][nbtwo]!=-1) return memo[pos][nbtwo];
int res=dp(nxt1[pos], nbtwo)+1;
if (nbtwo<y) cmin(res, dp(nxt2[pos], nbtwo+1));
return memo[pos][nbtwo]=res;
}
void solve() {
read(n, x, y);
a.clear(), a.resize(n); read(a);
nxt1.resize(n), nxt2.resize(n);
sort(all(a));
memo.assign(n, vector<short>(y+1, -1));
int l=1, r=1e9, ans=1e9;
while (l<=r) {
cur=(l+r)/2;
int pos1=0, pos2=0;
for (int i=0; i<n; i++) {
for (int j=0; j<=y; j++) memo[i][j]=-1;
while (pos1<n && a[pos1]<a[i]+cur) pos1++;
while (pos2<n && a[pos2]<a[i]+2*cur) pos2++;
nxt1[i]=pos1;
nxt2[i]=pos2;
}
if (dp(0, 0)<=x) {
ans=cur;
r=cur-1;
} else {
l=cur+1;
}
}
cout << ans << endl;
}
