/*
* @Author: MaxPhast
* @File: test.cpp
* @Date: 2026-04-13 21:02:51
*/
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ii pair <int , int>
#define iii pair <int , ii>
#define iiii pair <ii , ii>
#define FOR(i , l , r) for(int i = (l) , _r = (r) ; i <= _r ; ++ i)
#define FORD(i , r , l) for(int i = (r) , _l = (l) ; i >= _l ; -- i)
#define ALL(vec) vec.begin() , vec.end()
#define UNI(vec) sort(ALL(vec)) , vec.erase(unique(ALL(vec)) , vec.end())
#define pb push_back
#define MASK(i) (1ll << i)
#define BIT(mask , i) ((mask >> i) & 1ll)
#define ON(mask , i) (mask | MASK(i))
#define OFF(mask , i) (mask & (~MASK(i)))
#define TURN(mask , i) (mask ^ MASK(i))
#define BP(mask) __builtin_popcountll(mask)
#define sqr(x) (1ll * (x) * (x))
#define fi first
#define se second
#define oo (int)1e18
#define time() cerr << " \n " << "Time elapsed : " << 1000.0 * clock() / CLOCKS_PER_SEC << "ms."
#define IO(TASK) if(fopen(#TASK".INP" , "r")){freopen(#TASK".INP" , "r" , stdin); freopen(#TASK".OUT" , "w" , stdout);}
template <class X , class Y>
bool maxz(X &a , const Y b)
{
if(a < b)
{
a = b;
return true;
}
return false;
}
template <class X , class Y>
bool minz(X &a , const Y b)
{
if(a > b)
{
a = b;
return true;
}
return false;
}
namespace MaxPhast
{
const int N = 2e3 + 5;
int n , P , Q;
int a[N] , dp[N][N];
bool f(int w)
{
FOR(i , 0 , n)
FOR(j , 0 , P)
dp[i][j] = oo;
dp[0][0] = 0;
int p = 1 , q = 1;
FOR(i , 1 , n)
{
while(p <= n && (a[p] - a[i] + 1) <= w)
p ++;
while(q <= n && (a[q] - a[i] + 1) <= 2 * w)
q ++;
FOR(j , 0 , P)
{
if(j - 1 >= 0)
minz(dp[p - 1][j] , dp[i - 1][j - 1]);
minz(dp[q - 1][j] , dp[i - 1][j] + 1);
}
}
int res = oo;
FOR(j , 0 , P)
minz(res , dp[n][j]);
return res <= Q;
}
void solve()
{
cin >> n >> P >> Q;
FOR(i , 1 , n)
cin >> a[i];
sort(a + 1 , a + 1 + n);
minz(P , n);
minz(Q , n);
int l = 1 , r = 1e6 , res = 1e6 + 1;
while(l <= r)
{
int mid = l + r >> 1;
if(f(mid))
{
res = mid;
r = mid - 1;
}
else
l = mid + 1;
}
cout << res;
}
}
signed main()
{
ios_base :: sync_with_stdio(false) ; cin.tie(nullptr) ; cout.tie(nullptr) ;
IO(test);
MaxPhast :: solve();
time();
}
/*
*/
