#include <bits/stdc++.h>
#define int long long
#define pii pair<int, int>
#define fi first
#define se second
#define ld long double
#define vi vector<int>
#define vii vector<vector<int>>
#define all(v) (v).begin(), (v).end()
#define rep(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define per(i, b, a) for (int i = (b), _a = (a); i >= _a; --i)
using namespace std;
const int MOD = 1e9 + 7;
int add(int a, int b) {
a += b;
if (a >= MOD) a -= MOD;
return a;
}
int mul(int a, int b) {
(a *= b) %= MOD;
return a;
}
int ceil(int x, int y) {
return (x + y - 1) / y;
}
int bin_pow(int x, int y) {
int res=1;
while(y){if(y&1)res=res*x%MOD;x=x*x%MOD;y>>=1;}
return res;
}
const int INF = 1e17;
const int maxn = 1e6 + 5;
int n, p, q;
int a[maxn + 5];
int rw[maxn + 5], r2w[maxn + 5];
int dp[2005][2005];
bool check(int w) {
for (int i = 1; i <= n; ++i) {
for (int j = i; j <= n; ++j) {
if (a[j] - a[i] + 1 <= w)
rw[i] = j;
if (a[j] - a[i] + 1 <= 2 * w)
r2w[i] = j;
else
break;
}
}
memset(dp, 0, sizeof dp);
dp[1][0] = rw[1];
dp[0][1] = r2w[1];
for (int i = 0; i <= p; ++i) {
for (int j = 0; j <= q; ++j) {
if (dp[i][j] == n) return true;
if (i < p)
dp[i + 1][j] = max(dp[i + 1][j], rw[dp[i][j] + 1]);
if (j < q)
dp[i][j + 1] = max(dp[i][j + 1], r2w[dp[i][j] + 1]);
}
}
return false;
}
void solve(int tc) {
cin >> n >> p >> q;
for (int i = 1; i <= n; ++i) cin >> a[i];
if (p + q >= n) {
cout << 1;
return;
}
sort(a + 1, a + n + 1);
int l = 1, r = a[n], ans;
while (l <= r) {
int mid = (l + r) >> 1;
if (check(mid)) {
ans = mid;
r = mid - 1;
} else {
l = mid + 1;
}
}
cout << ans;
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int tc = 1;
//cin >> tc;
for (int i = 1; i <= tc; ++i) {
solve(i);
}
}
