#include <bits/stdc++.h>
#define fast ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define ff first
#define ss second
#define For(i,a,b) for(int i = (a), _b= (b) ; i<=_b ; i++)
#define pii pair<int,int>
#define ll long long
#define all(a) a.begin(),a.end()
#define pll pair<ll,ll>
#define pb push_back
#define AF "EVENTS"
using namespace std ;
const int N = 2100;
const int MOD = 998244353;
int f[N][N],n,w1,w2,a[N];
bool minimize(int &a,int b)
{
if(a>b){
a=b;return true;
}else return false;
}
bool check(int mid)
{
int l1=1,l2=1;
memset(f,0x3f,sizeof f);
memset(f[0],0,sizeof f[0]);
For(i,1,n)
{
while(a[i]-a[l1]+1>mid) l1++;
while(a[i]-a[l2]+1>2*mid) l2++;
For(j,0,w1)
{
minimize(f[i][j+1],f[l1-1][j]);
minimize(f[i][j],f[l2-1][j]+1);
}
}
For(j,0,w1) if(f[n][j]<=w2) return true;
return false;
}
void enter()
{
cin >> n >> w1 >> w2;
if(w1+w2>=n){cout << 1; return;}
For(i,1,n) cin >> a[i];
sort(&a[1],&a[n+1]);
int l = 1,r = 1e9;
while(l<=r)
{
int mid = (l+r)>>1;
if(check(mid)) r = mid-1;
else l = mid+1;
}
cout << r+1;
}
void solve()
{
}
int main()
{
fast;
//freopen(AF".inp","r",stdin);
// freopen(AF".out","w",stdout);
enter();
solve();
}
