#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
//using namespace __gnu_pbds;z
#define pb push_back
#define ff first
#define ss second
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define int long long
//#define ordst tree<pair<int,int>, null_type, less<pair<int,int>>, rb_tree_tag , tree_order_statistics_node_update >
//#define double long double
template <class F, class _S>
bool chmin(F &u, const _S &v){
bool flag = false;
if ( u > v ){
u = v; flag |= true;
}
return flag;
}
template <class F, class _S>
bool chmax(F &u, const _S &v){
bool flag = false;
if ( u < v ){
u = v; flag |= true;
}
return flag;
}
const int N = (1<<18) +1, inf = 1e18+200;
//int mod = 998244353;
//int mod = 1000000007;
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//#define rnd(l, r) uniform_int_distribution <int> (l, r)(rng)
void solve(){
int n, p, q;
cin >> n >> p >> q;
vector<int> a(n);
for(int &i:a)cin >> i;
if(p+q >= n){
cout << 1 << '\n';
return;
}
a.pb(0);a.pb(inf);
sort(all(a));
//for(int &i:a)cout << i << ' ';
//cout << '\n';
auto ok = [&](int m)->bool{
vector<vector<int>> dp(p+1, vector<int> (q+1));
dp[0][0] = 0;
for(int x = 0; x <= p; x++){
for(int y = 0; y <= q; y++){
int cur = dp[x][y] + 1;
if(cur > n)return true;
//small
//cout << x << ' ' << y << ' ' << cur << '\n';
if(x < p){
int l = lower_bound(all(a), a[cur] + m) - a.begin();
if(a[l] >= a[cur] + m)l--;
chmax(dp[x+1][y], l);
//cout << l << ' ' << a[cur] + m << " x+1 \n";
}
if(y < q){
int l = lower_bound(all(a), a[cur] + m*2) - a.begin();
if(a[l] >= a[cur] + m*2)l--;
chmax(dp[x][y+1], l);
//cout << l << ' ' << a[cur]+2*m << " y+1 \n";
}
}
}
return false;
};
//bool s = ok(4);
//cout << s << '\n';
int l = 1, r = a[n]-a[1], ans = 1;
while(l <= r){
int m = (l+r)>>1;
//cout << m << ' ' << ok(m) << '\n';
if(ok(m)){
ans = m;
r = m-1;
}else l = m+1;
}
cout << ans << '\n';
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int tt = 1;
//cin >> tt;
while(tt--){
solve();
}
}
