#include <bits/stdc++.h>
#define fw(i,l,r) for (int i=l;i<r;i++)
using namespace std;
int n,p,q;
int a[2001];
int fars[2001];
int farl[2001];
int dp[2001][2001];
bool check(int w)
{
for(int i=0;i<n;i++)
{
fars[i] = upper_bound(a,a+n,a[i]+w-1) - a;
farl[i] = upper_bound(a,a+n,a[i]+2*w-1) - a;
}
memset(dp,-1,sizeof(dp));
dp[0][0] = 0;
for(int i=0;i<=p;i++)
{
for(int j=0;j<=q;j++)
{
if(dp[i][j]!=-1)
{
if(dp[i][j]==n)
return true;
dp[i+1][j] = max(dp[i+1][j],fars[dp[i][j]]);
dp[i][j+1] = max(dp[i][j+1],farl[dp[i][j]]);
}
}
}
return false;
}
signed main()
{
cin>>n>>p>>q;
for(int i=0;i<n;i++)
cin>>a[i];
if(p+q>=n)
{
cout<<1;
return 0;
}
sort(a,a+n);
//for(int i=0;i<n;i++)
//cout<<a[i]<<" ";
int L=1,R=1e9;
while(L!=R)
{
int mid = (L+R)/2;
if(check(mid))
R = mid;
else
L = mid+1;
}
cout<<L;
}
