#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define SZ(x) (int)(x.size())
#define ALL(x) (x.begin(),x.end())
#define pb push_back
#ifdef BALBIT
#define bug(...) cerr<<"#"<<__LINE__<<": "<<#__VA_ARGS__<<": ", _do(__VA_ARGS__)
template<typename T> void _do(T && x) {cerr<<x<<endl;}
template<typename T, typename ...S> void _do(T && x, S &&...y) {cerr<<x<<", "; _do(y...);}
#define IOS()
#else
#define IOS() ios::sync_with_stdio(0), cin.tie(0)
#define bug(...)
#define endl '\n'
#endif // BALBIT
const int maxn = 2004;
int n,p,q;
int a[maxn];
int pn[maxn], qn[maxn];
int dp[maxn][maxn];
bool ok(int w) {
bug(w);
int j = n-1;
for (int i = n-1; i>=0; --i) {
// pn records the last THING that it can reach
while (a[j] - a[i] >= w) --j;
pn[i] = j;
}
j = n-1;
for (int i = n-1; i>=0; --i) {
// qn records the last THING that it can reach
while (a[j] - a[i] >= 2*w) --j;
qn[i] = j;
}
pn[n] = qn[n] = n-1;
for (int i = 0; i<maxn; ++i) fill(dp[i], dp[i]+ maxn, -0x3f3f3f3f);
dp[0][0] = -1;
for (int i = 0; i<=p; ++i) {
for (int j = 0; j<=q; ++j) {
if (i || j) {
dp[i][j] = max(i?pn[dp[i-1][j]+1]:-1, j?qn[dp[i][j-1]+1]:-1);
}
}
}
bug(w,dp[p][q]);
return dp[p][q] >=n-1;
}
signed main(){
IOS();
cin>>n>>p>>q;
for (int i = 0; i<n; ++i) cin>>a[i];
sort(a, a+n);
p = min(p,n);
q = min(q,n);
int l = 1, r = 1e9+1;
while (l!=r) {
int mid = (l+r)/2;
if (ok(mid)) {
r = mid;
}else{
l = mid+1;
}
}
cout<<l<<endl;
}
