#include<bits/stdc++.h>
#define ll long long
#define f first
#define s second
using namespace std;
const int maxn=2e3+5;
int n,p,q;
int a[maxn];
int R[maxn],R2[maxn];
int dp[maxn][maxn];
// p small
// q large
bool check(int w)
{
for(int i=1;i<=n;i++){
R[i]=upper_bound(a+1,a+n+1,a[i]+w-1)-a-1;
R2[i]=upper_bound(a+1,a+n+1,a[i]+2*w-1)-a-1;
}
for(int i=0;i<=p;i++){
for(int j=0;j<=q;j++) dp[i][j]=0;
}
dp[0][0]=0;
for(int x=0;x<=p;x++){
for(int y=0;y<=q;y++){
if(x>0){
int id=dp[x-1][y];
dp[x][y]=max(dp[x][y],R[id+1]);
}
if(y>0){
int id=dp[x][y-1];
dp[x][y]=max(dp[x][y],R2[id+1]);
}
if(dp[x][y]>=n) return true;
}
}
return dp[p][q]==n;
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
cin>>n>>p>>q;
for(int i=1;i<=n;i++){
cin>>a[i];
}
sort(a+1,a+n+1);
if(p+q>=n){
cout<<1;
return 0;
}
int l=1,r=a[n],ans;
while(l<=r){
int mid=(l+r)/2;
if(check(mid)){
ans=mid;
r=mid-1;
}
else l=mid+1;
}
cout<<ans;
}
