#include <bits/stdc++.h>
using namespace std;
#define endl "\n"
#define pb push_back
#define ff first
#define ss second
#define mod 1000000007
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
int n,p,q;
const int N = 2e3 + 5;
int v[N];
vector<vector<vector<short>>> dp;
int get(int val){
int l = 0,r = n-1;
while(l < r){
int m = (l + r) / 2;
if(val <= v[m]) r = m;
else l = m + 1;
}
return l + (v[n-1] < val);
}
bool f(int pos,int p,int q,int w){
if(p < 0 || q < 0) return false;
if(pos == n) return true;
if(dp[pos][p][q] != -1) return dp[pos][p][q];
int a = get(v[pos] + w);
int b = get(v[pos] + 2*w);
dp[pos][p][q] = (f(a,p-1,q,w) || f(b,p,q-1,w));
return dp[pos][p][q];
}
bool check(int m){
dp.assign(n,vector<vector<short>>(p+1,vector<short>(q+1,-1)));
return f(0,p,q,m);
}
void solve(){
cin >> n >> p >> q;
for(int i=0;i<n;i++){
cin >> v[i];
}
if(p + q >= n){
cout << 1 << endl;
return;
}
sort(v,v+n);
int l = 1,r = 1e9;
while(l < r){
int m = (l + r) / 2;
if(check(m)) r = m;
else l = m + 1;
}
cout << l << endl;
}
signed main(){
ios::sync_with_stdio(0);
cin.tie(0);
int t = 1;
// cin >> t;
while(t--)
solve();
return 0;
}
