#include <iostream>
#include <algorithm>
int n, p, q;
int a[2005], nextsmall[2005], nextlarge[2005], dp[2005][2005];
bool Check(int value)
{
for(int i = 0; i < n; i++)
{
nextsmall[i] = std::upper_bound(a, a + n + 1, a[i] + value - 1) - a;
nextlarge[i] = std::upper_bound(a, a + n + 1, a[i] + value * 2 - 1) - a;
}
for(int i = 0; i <= p; i++)
{
if(i > 0)
{
dp[i][0] = nextsmall[dp[i - 1][0]];
if(dp[i][0] == n)
{
return true;
}
}
else
{
dp[i][0] = 0;
}
for(int j = 1; j <= q; j++)
{
dp[i][j] = 0;
if(i)
{
dp[i][j] = std::max(dp[i][j], nextsmall[dp[i - 1][j]]);
}
dp[i][j] = std::max(dp[i][j], nextlarge[dp[i][j - 1]]);
if(dp[i][j] == n)
{
return true;
}
}
}
return false;
}
int main()
{
std::ios_base::sync_with_stdio(false);
std::cin.tie(0);
std::cout.tie(0);
std::cin >> n >> p >> q;
p = std::min(p, n);
q = std::min(q, n);
for(int i = 0; i < n; i++)
{
std::cin >> a[i];
}
a[n] = 2e9;
std::sort(a, a + n);
int l = 1, r = 1e9 / 2;
while(l < r)
{
int mid = (l + r) >> 1;
if(Check(mid))
{
r = mid;
}
else
{
l = mid + 1;
}
}
std::cout << l;
}
