#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define ff first
#define ss second
#define pii pair<int, int>
#define sz(v) (int)(v).size()
#define all(v) (v).begin(), (v).end()
int main() {
ios::sync_with_stdio(false); cin.tie(nullptr);
int n, p, q;
cin >> n >> p >> q;
p = min(n, p); q = min(n, q);
vector<int> a(n + 1, INT_MIN);
for (int i = 1; i <= n; i++)
cin >> a[i];
sort(1 + all(a));
auto chk = [&](int md) -> bool {
int x = 0, y = 0;
vector<vector<pii>> dp(n + 1); dp[0] = {{0, 0}};
for (int i = 1; i <= n; i++) {
while (x < n && a[x + 1] <= a[i] - md) x++;
while (y < n && a[y + 1] <= a[i] - (md << 1)) y++;
vector<pii> v;
for (auto j : dp[x])
if (j.ff < p) v.push_back({j.ff + 1, j.ss});
for (auto j : dp[y])
if (j.ss < q) v.push_back({j.ff, j.ss + 1});
sort(v.begin(), v.end());
for (int j = 0; j < sz(v); j++)
if (!j || dp[i].back().ss > v[j].ss) dp[i].push_back(v[j]);
assert(sz(dp[i]) < n + 2);
}
return !dp[n].empty();
};
int l = 1, r = 1;
while (!chk(r)) r <<= 1;
while (l <= r) {
int md = (l + r) >> 1;
if (!chk(md)) l = md + 1;
else r = md - 1;
}
cout << l;
}
