#define here cerr<<"===========================================\n"
#define dbg(x) cerr<<#x<<": "<<x<<endl;
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#define ld double
#define ll long long
#define llinf 100000000000000000LL // 10^17
#define pb push_back
#define popb pop_back
#define fi first
#define sc second
#define endl '\n'
#define pll pair<ll,ll>
#define pld pair<ld,ld>
#define sz(a) (ll)(a.size())
#define all(a) a.begin(),a.end()
#define ceri(a,l,r) {cerr<<#a<<": ";for(ll i_ = l;i_<=r;i_++) cerr<<a[i_]<< " ";cerr<<endl;}
#define daj_mi_malo_vremena ios_base::sync_with_stdio(false);cerr.tie(0);cout.tie(0);cin.tie(0);
using namespace std;
using namespace __gnu_pbds;
/*
ll add(ll x,ll y){
x+=y;
if(x<0){
x%=mod;
x+=mod;
}else{
if(x>=mod) x%=mod;
}
return x;
}
ll mul(ll a,ll b){
ll ans = (a*b)%mod;
if(ans<0) ans+=mod;
return ans;
}
typedef tree<int,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
typedef tree<int,null_type,less_equal<ll>,rb_tree_tag,tree_order_statistics_node_update> ordered_multiset;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll rnd(ll l,ll r){
return uniform_int_distribution<ll>(l,r)(rng);
}
*/
#define maxn 2005
ll n,p,q;
ll a[maxn];
ll dp[maxn][maxn];
ll bs(ll i,ll w){
ll l = i,r = n,mid,rez = i;
while(l<=r){
mid = (l+r)/2;
if(a[mid]-a[i]+1<=w) l = mid+1,rez = mid;
else r = mid-1;
}
return rez;
}
bool moe(ll w){
for(ll i = 0;i<=n;i++) for(ll j = 0;j<=n;j++) dp[i][j] = 0;
dp[0][0] = 0;
for(ll i = 0;i<=p;i++){
for(ll j = 0;j<=q;j++){
dp[i+1][j] = max(dp[i+1][j],bs(dp[i][j]+1,w));
dp[i][j+1] = max(dp[i][j+1],bs(dp[i][j]+1,2*w));
}
}
return dp[p][q]>=n;
}
int main(){
daj_mi_malo_vremena
cin >> n >> p >> q;
for(ll i = 1;i<=n;i++) cin >> a[i];
sort(a+1,a+1+n);
if(p+q>=n){cout<<1<<endl; return 0;}
ll l = 1,r = 1e9,mid,rez = 1e9;
while(l<=r){
mid = (l+r)/2;
if(moe(mid)) r = mid-1,rez = mid;
else l = mid+1;
}
cout<<rez<<endl;
return 0;
}
