#include <bits/stdc++.h>
using namespace std;
#define int long long
#define fr first
#define sc second
#define pb push_back
#define all(x) x.begin(),x.end()
#define sp << " " <<
#define inf 1e9
#define N 2000
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef tuple<int,int,int> tiii;
typedef pair<int,int> pii;
int n,p,q,a[N+5];
bool f(int w){
pii dp[n];
dp[0]={0,0};
for(int i=1;i<=n;i++){
dp[i]={inf,inf};
for(int j=0;j<i;j++){
if(a[i]-a[j+1]+1<=w && dp[j].fr-dp[j].sc!=p)
dp[i]=min(dp[i],make_pair(dp[j].fr+1,dp[j].sc));
else if(a[i]-a[j+1]+1<=2*w && dp[j].sc!=q)
dp[i]=min(dp[i],make_pair(dp[j].fr+1,dp[j].sc+1));
}
}
//~ for(int i=0;i<=n;i++)
//~ cout << dp[i].fr sp dp[i].sc << endl;
return (dp[n].fr!=inf);
}
void solve(){
cin >> n >> p >> q;
for(int i=1;i<=n;i++) cin >> a[i];
if(n<=p+q){
cout << 1;
return;
}
sort(a+1,a+n+1);
int l=1,r=inf;
while(l<r){
int mid=(l+r)/2;
if(f(mid)) r=mid;
else l=mid+1;
}
cout << l << endl;
}
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);cout.tie(NULL);
int test=1;
//~ cin >> test;
while(test--) solve();
}
