#include<bits/stdc++.h>
using namespace std;
#define int long long
const int N = 2005;
int n, p, q, ans;
int a[N], cnt[N], max2w[N], maxw[N];
int f[N][N];
bool check(int mid){
int cur1 = 1, cur2 = 1;
for (int i = 1; i <= n; i++){
for (; cur1 <= n && a[cur1] - a[i] + 1 <= mid; cur1++);
maxw[i] = cur1 - 1;
for (; cur2 <= n && a[cur2] - a[i] + 1 <= 2 * mid; cur2++);
max2w[i] = cur2 - 1;
}
memset(f, -1, sizeof(f));
f[1][0] = maxw[1];
f[0][1] = max2w[1];
if (maxw[1] == n || max2w[1] == n){
return true;
}
for (int i = 0; i <= p; i++){
for (int j = 0; j <= q; j++){
if (f[i][j] != -1){
if (f[i][j] == n){
return true;
}
f[i][j + 1] = max(f[i][j + 1], max2w[f[i][j] + 1]);
f[i + 1][j] = max(f[i + 1][j], maxw[f[i][j] + 1]);
}
}
}
return false;
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cin >> n >> p >> q;
a[n + 1] = 1e9;
for (int i = 1; i <= n; i++){
cin >> a[i];
}
sort(a + 1, a + n + 1);
if (p + q >= n){
cout << 1;
return 0;
}
int l = 1, r = a[n] - a[1] + 1;
while (l <= r){
int mid = (l + r) / 2;
bool kt = check(mid);
if (kt){
ans = mid;
r = mid - 1;
}
else{
l = mid + 1;
}
}
cout << ans;
}
