#include <iostream>
#include <set>
using namespace std;
int n, p, q, sz;
int a[2005] {};
bool check(int w) {
int dp[2005][2005]{}; //dp[small cameras used][large cameras used] = max index covered so far
for(int i = 0; i<=p; i++) {
for(int j = 0; j<=q; j++) {
int pos = dp[i][j]+1, next;
//small cam
if(i!=p) {
next = pos;
while(next < sz) {
if(a[next+1] - a[pos] <= w-1) next++;
else break;
}
dp[i+1][j] = max(dp[i+1][j], min(sz,next));
}
//large cam
if(j!=q){
next = pos;
while(next<sz) {
if(a[next+1] - a[pos] <= 2*w-1) next++;
else break;
}
dp[i][j+1] = max(dp[i][j+1], min(next,sz));
}
}
}
return (dp[p][q] == sz);
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n >> p >> q;
set<int> sec;
for(int i = 0; i<n; i++) {
int a; cin >> a;
sec.insert(a);
}
if(p+q >= n) {
cout << 1;
return 0;
}
int i = 1;
for(int k : sec) {
a[i] = k; i++;
}
sz = i-1;
int l = 1, r = *sec.rbegin(), ans;
while(l<=r) {
int w = (l+r)/2;
if(check(w)) {
ans = w;
r = w-1;
} else l = w+1;
}
cout << ans;
return 0;
}
