#include <bits/stdc++.h>
using namespace std;
int n, p, q;
int a[2001];
bool moze(int w){
int sm = p, big = q;
for(int i = 0; i < n-1; i++){
int dst = a[i+1] - a[i] + 1;
if(dst > 2*w){
if(sm > 0) sm--;
else big--;
}
else if(dst > w){
if(big > 0) {
big--;
i++;
}
else sm--;
}
else{
sm--;
int c = a[i];
i++;
while(i < n-1 && a[i] - c + 1 <= w) i++;
i--;
}
}
return sm >0 || big > 0;
}
signed main(){
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> n >> p >> q;
for(int i = 0; i < n; i++) cin >> a[i];
sort(a, a + n);
int l = 1, r = 1e9;
while(l <= r){
int m = (l+r)>>1;
if(moze(m)){
r = m-1;
}
else l = m+1;
}
cout << r << '\n';
return 0;
}
