//khodaya khodet komak kon
#include <bits/stdc++.h>
#define F first
#define S second
#define pb push_back
#define all(x) x.begin(), x.end()
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math")
#define int long long
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
const int N = 2000 + 10;
const ll MOD = 1000000000 + 7;
const ll INF = 1000000000000000010;
const ll LOG = 25;
int dp[N][N], n, p, q, a[N], nxt[N], nxt2[N];
bool isval(int w){
//cout << w << ' ';
memset(dp, 0, sizeof dp);
memset(nxt, 0, sizeof nxt);
memset(nxt2, 0, sizeof nxt2);
int pnt = 1, pnt2 = 1;
for (int i = 1; i <= n - 1; i++){
while (a[pnt + 1] - a[i] <= w - 1) pnt++;
while (a[pnt2 + 1] - a[i] <= 2 * w - 1) pnt2++;
nxt[i] = pnt;
nxt2[i] = pnt2;
}
for (int i = 0; i <= p; i++) for (int j = 0; j <= q; j++){
int x = dp[i][j];
//cout << i << ' ' << j << ' ' << dp[i][j] << '\n';
x++;
if (dp[i][j] >= n - 1) return 1;
dp[i + 1][j] = max(dp[i + 1][j], nxt[x]);
dp[i][j + 1] = max(dp[i][j + 1], nxt2[x]);
}
// cout << dp[p][q] << '\n';
return (dp[p][q] >= n - 1);
}
int32_t main(){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> p >> q;
for (int i = 1; i <= n; i++) cin >> a[i];
sort(a + 1, a + n + 1);
n++;
a[n] = INF;
int l = 0, r = 1000000000;
while (r - l > 1){
int md = (l + r) >> 1;
if (isval(md)) r = md;
else l = md;
}
cout << r;
// isval(32);
return 0;
}
