#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;
typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;
typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)
#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()
const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 100001;
int N,P,Q, dp[2001][2001], nexLarge[2001], nexSmall[2001];
vi A;
bool ok(int w) {
F0R(i,P+1) F0R(j,Q+1) dp[i][j] = 0;
nexLarge[N] = nexSmall[N] = N;
F0Rd(i,N) {
nexLarge[i] = nexLarge[i+1];
while ((ll)A[i]+2*w-1 < A[nexLarge[i]-1]) nexLarge[i] --;
nexSmall[i] = nexSmall[i+1];
while ((ll)A[i]+w-1 < A[nexSmall[i]-1]) nexSmall[i] --;
}
F0R(i,P+1) F0R(j,Q+1) {
if (dp[i][j] >= N) return 1;
if (i < P) dp[i+1][j] = max(dp[i+1][j],nexSmall[dp[i][j]]);
if (j < Q) dp[i][j+1] = max(dp[i][j+1],nexLarge[dp[i][j]]);
}
return 0;
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> N >> P >> Q; A.resize(N);
F0R(i,N) cin >> A[i];
sort(all(A));
Q = min(Q,N);
P = min(P,N-Q);
int lo = 1, hi = 1000000000;
while (lo < hi) {
int mid = (lo+hi)/2;
if (ok(mid)) hi = mid;
else lo = mid+1;
}
cout << lo;
}
/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( )
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/
