#include <bits/stdc++.h>
#define int long long
#define debug cout << "ok\n";
#define SQR(x) (1LL * ((x) * (x)))
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define pii pair<int,int>
#define pli pair<ll,int>
#define vi vector<int>
#define FAST ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef unsigned int ui;
using namespace std;
const int M = 1e9 + 7;
const int INF = 1e9 + 7;
const ll INFLL = (ll)2e18 + 7LL;
const ld PI = acos(-1);
const int dx[] = {1, -1, 0, 0, -1, 1, 1, -1};
const int dy[] = {0, 0, 1, -1, -1, -1, 1, 1};
template<class _, class __>
bool minimize(_ &x, const __ y){
if(x > y){
x = y;
return true;
} else return false;
}
template<class _, class __>
bool maximize(_ &x, const __ y){
if(x < y){
x = y;
return true;
} else return false;
}
template<class _,class __>
void Add(_ &x, const __ y) {
x += y;
if (x >= M) {
x -= M;
}
return;
}
template<class _,class __>
void Diff(_ &x, const __ y) {
x -= y;
if (x < 0) {
x += M;
}
return;
}
//--------------------------------------------------------------
const int MaxN = 2007;
int n,p,q,f[MaxN][MaxN],a[MaxN];
bool check(int len) {
for (int j=0;j<=q;j++) f[0][j] = 0;
for (int i=1,p1=1,p2=2;i<=n;i++) {
for (int j=0;j<=q;j++) {
f[i][j] = INF;
}
while (a[i] - a[p1] + 1 > len) p1++;
while (a[i] - a[p2] + 1 > 2 * len) p2++;
for (int j=0;j<=q;j++) {
if (j) minimize(f[i][j],f[p2-1][j-1]);
minimize(f[i][j],f[p1-1][j] + 1);
}
}
// cout << len << ' ' << f[n][q] << '\n';
return f[n][q] <= p;
}
void sol() {
cin >> n >> p >> q;
for (int i=1;i<=n;i++) cin >> a[i];
sort(a+1,a+n+1);
if (p + q >= n) {
cout << 1;
return;
}
// debug;
int res = 0;
int l = 1, r = 1e9;
while (l <= r) {
int mid = (l+r) >> 1;
if (check(mid)) {
res = mid;
r = mid - 1;
}
else l = mid + 1;
}
cout << res;
}
signed main() {
// freopen("test.inp","r",stdin);
// freopen("test.out","w",stdout);
FAST
int t=1;
// cin >> t;
while (t--) sol();
}
