#include <iostream>
#include <cstdio>
#include <cmath>
#include <vector>
#define task ""
using namespace std;
using ll = long long;
using ld = long double;
const int N = 1e5 + 2;
const int Inf = 1e9 + 7;
int n, T, k;
int x[N];
void Read()
{
cin >> n >> k >> T;
for (int i = 1; i <= n; ++i)
cin >> x[i];
}
bool Check(int v)
{
vector<vector<bool>> dp(n + 5, vector<bool>(n + 5));
dp[k][k] = 1;
for (int i = 2; i <= n; ++i)
for (int j = 1; j <= n - i + 1; ++j)
if ((dp[j][j + i - 2] || dp[j + 1][j + i - 1]) && 2ll * T * (i - 1) >= ceil((ld)1.0 * (x[j + i - 1] - x[j]) / v))
dp[j][j + i - 1] = 1;
return dp[1][n];
}
void Solve()
{
int l = 0, m, h = 1e9 + 7;
while (l <= h)
{
m = (l + h) / 2;
if (!Check(m))
l = m + 1;
else
h = m - 1;
}
cout << l;
}
int32_t main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
if (fopen(task ".INP", "r"))
{
freopen(task ".INP", "r", stdin);
freopen(task ".OUT", "w", stdout);
}
Read();
Solve();
}
