#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pll pair<ll,ll>
#define pii pair<int,int>
#define fs first
#define sc second
#define tlll tuple<ll,ll,ll>
const int mxn = 2020;
int dp[mxn][mxn];
int N;
int arr[mxn];
int pt1,pt2;
int P,Q;
bool check(int len){
pt1 = 0,pt2 = 0;
for(int i = 1;i<=N;i++){
while(arr[i]-arr[pt1]>=len)pt1++;
while(arr[i]-arr[pt2]>=len*2)pt2++;
for(int j = 0;j<=N;j++){
dp[i][j] = 1e9;
if(j)dp[i][j] = min(dp[i][j],dp[pt2-1][j-1]);
dp[i][j] = min(dp[i][j],dp[pt1-1][j]+1);
}
}
return dp[N][Q]<=P;
}
int main(){
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin>>N>>P>>Q;
for(int i = 1;i<=N;i++)cin>>arr[i];
if(P+Q>=N){
cout<<1;
return 0;
}
arr[0] = -1e9-10;
sort(arr+1,arr+N+1);
int l = 0,r = 1e9;
while(l != r){
int mid = (l+r)>>1;
if(check(mid))r = mid;
else l = mid+1;
}
cout<<l<<'\n';
return 0;
}
