#include <bits/stdc++.h>
#define pb push_back
#define endl ("\n")
#define all(aa) aa.begin(), aa.end()
typedef long long ll;
using namespace std;
int main(){
int n, p, q;
cin >> n >> p >> q;
// p kucuk, q buyuk
vector<ll> a(n);
for(int i = 0; i < n; i++) cin >> a[i];
if(p + q >= n){
cout << 1 << endl;
exit(0);
}
a.pb(0);
sort(all(a));
function<int(int, ll)> get = [&](int pos, ll w){
if(pos + 1 > n) return n;
ll val = a[pos + 1] + w - 1;
int ind = prev(upper_bound(all(a), val)) - a.begin();
return ind;
};
ll tl = 0, tr = 1e9 + 5;
vector<vector<int>> dp(p + 1, vector<int>(q + 1));
function<int(ll)> ok = [&](ll w){
for(int i = 0; i <= p; i++) for(int j = 0; j <= q; j++) dp[i][j] = 0;
for(int i = 0; i <= p; i++){
for(int j = 0; j <= q; j++){
if(i - 1 >= 0){
dp[i][j] = max(dp[i][j], get(dp[i - 1][j], w));
}
if(j - 1 >= 0){
dp[i][j] = max(dp[i][j], get(dp[i][j - 1], w * 2));
}
}
}
return dp[p][q] >= n;
};
while(tr - tl > 1){
ll tm = (tl + tr + 1) / 2;
if(ok(tm))
tr = tm;
else
tl = tm;
}
cout << tr << endl;
}
