#include <bits/stdc++.h>
#pragma GCC optimize ("O3,unroll-loops")
#pragma GCC target ("avx2,bmi,bmi2,popcnt,lzcnt")
#define fi first
#define se second
using namespace std;
const int N=2005;
int64_t a[N];
int dp[N][N];
int n,p,q;
bool check(int64_t w){
dp[0][0]=0;
for(int i=0;i<p;i++){
for(int j=0;j<=q;j++){
//if(dp[i][j]==n||(j>0&&dp[i+1][j-1]==n))continue;
int64_t start=dp[i][j];
int s=0;
while(start+s<n&&a[start+s]-a[start]+1<=w){
s++;
}
if(j==0){
dp[i+1][j]=dp[i][j]+s;
//cout<<"check0:"<<i+1<<' '<<j<<' '<<dp[i+1][j]<<'\n';
continue;
}
start=dp[i+1][j-1];
int l=0;
while(start+l<n&&a[start+l]-a[start]+1<=2*w){
l++;
}
dp[i+1][j]=max(dp[i][j]+s,dp[i+1][j-1]+l);
//cout<<"check1:"<<i+1<<' '<<j<<' '<<dp[i+1][j]<<'\n';
}
}
//cout<<dp[p][q]<<' '<<w<<'\n';
return dp[p][q]==n;
}
void solve(){
cin>>n>>p>>q;
if(p+q>=n){
cout<<1<<'\n';
return;
}
for(int i=0;i<n;i++){
cin>>a[i];
}
sort(a,a+n);
/*
vector<int64_t> mids;
for(int i=0;i<n;i++){
for(int j=i;j<n;j++){
mids.push_back(a[j]-a[i]+1);
mids.push_back((a[j]-a[i]+2)/2);
}
}
sort(mids.begin(),mids.end());
mids.erase(unique(mids.begin(),mids.end()),mids.end());
*/
int64_t l=1;
int64_t r=1000000000;
while(l<r){
int64_t mid=(l+r)/2;
bool c=check(mid);
if(c){
r=mid;
}
else{
l=mid+1;
}
}
/*
for(int i=0;i<mids.size();i++){
cout<<mids[i]<<' ';
}
cout<<'\n';
cout<<mids[l]<<'\n';
*/
cout<<l<<'\n';
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int64_t t=1;
//cin>>t;
while(t--){
solve();
}
return 0;
}
