#include <bits/stdc++.h>
using namespace std;
const int len = 2e3+5, inf = 1e9;
int n, p, q, a[len];
int nex[2][len], pre[2][len], dp[len][len], best[len][len];
/*int finduse(int pos, int use1){
if (pos == 0 && use1 == 0) return 0;
if (pos == 0 && use1 != 0) return inf;
if (best[pos][use1] != -1) return best[pos][use1];
int ans = inf;
if (use1 > 0)
ans = min(ans, finduse(pre[0][pos], use1-1));
ans = min(ans, finduse(pre[1][pos], use1)+1);
return best[pos][use1] = ans;
}
int solve(int pos, int use1){
if (pos == n+1) return 1;
if (dp[pos][use1] != -1) return dp[pos][use1];
int use2 = finduse(pos-1, use1), ans = 0;
if (use1 < pp)
ans = max(ans, solve(nex[0][pos], use1+1));
if (use2 < qq)
ans = max(ans, solve(nex[1][pos], use1));
//if (hey) printf("pos = %d, use1 = %d, use2 = %d, ans = %d\n", pos, use1, use2, ans);
return dp[pos][use1] = ans;
}*/
bool check(int w){
for (int i = 1, j1 = 1, j2 = 1; i <= n; i++){
while (j1 <= n && a[j1]-a[i]+1 <= w) j1++;
while (j2 <= n && a[j2]-a[i]+1 <= 2*w) j2++;
nex[0][i] = j1;
nex[1][i] = j2;
}
for (int i = n, j1 = n, j2 = n; i >= 1; i--){
while (j1 >= 1 && a[i]-a[j1]+1 <= w) j1--;
while (j2 >= 1 && a[i]-a[j2]+1 <= 2*w) j2--;
pre[0][i] = j1;
pre[1][i] = j2;
}
/*qq = q, pp = p;
if (q < p){
swap(pp, qq);
for (int i = 1; i <= n; i++){
swap(nex[0][i], nex[1][i]);
swap(pre[0][i], pre[1][i]);
}
}*/
for (int i = 1; i <= p; i++)
best[0][i] = inf;
best[0][0] = 0;
for (int i = 1; i <= n; i++)
for (int j = 0; j <= p; j++){
best[i][j] = min(inf, best[pre[1][i]][j]+1);
if (j > 0) best[i][j] = min(best[i][j], best[pre[0][i]][j-1]);
}
for (int i = 0; i <= p; i++)
dp[n+1][i] = 1;
for (int i = n; i >= 1; i--)
for (int j1 = 0; j1 <= p; j1++){
int j2 = best[i-1][j1];
dp[i][j1] = 0;
if (j1 < p) dp[i][j1] = (dp[i][j1] | dp[nex[0][i]][j1+1]);
if (j2 < q) dp[i][j1] = (dp[i][j1] | dp[nex[1][i]][j1]);
}
return dp[1][0];
}
int bs(){
int l = 1, r = inf/2, ans;
while (l <= r){
int mid = (l+r)/2;
if (check(mid)){
ans = mid;
r = mid-1;
}
else
l = mid+1;
}
return ans;
}
void read(int &res){
char c;
while (c = getchar(), c < '0' || c > '9'){}
res = c-'0';
while (c = getchar(), c >= '0' && c <= '9')
res = 10*res+c-'0';
}
int main(){
read(n), read(p), read(q);
for (int i = 1; i <= n; i++)
read(a[i]);
sort(a+1, a+n+1);
if (p+q >= n) printf("1\n");
else printf("%d\n", bs());
return 0;
}
