#include <bits/stdc++.h>

using namespace std;

int n, k;
vector<int> a;
vector<vector<int>> v;

int solve(int i) {
  if (i == n) {
    if (find(v.begin(), v.end(), vector<int>()) != v.end()) return 0;
    vector<double> ave;
    for (auto& u : v) ave.emplace_back(accumulate(u.begin(), u.end(), 0.0) / u.size());
    auto m = minmax_element(ave.begin(), ave.end());
    return ceil(*m.second - *m.first);
  }
  int res = 0;
  for (int j = 0; j < k; ++j) {
    v[j].emplace_back(a[i]);
    res = max(res, solve(i + 1));
    v[j].pop_back();
  }
  return res;
}

int main() {
  cin >> n >> k;
  a.resize(n);
  for (int& i : a) cin >> i;
  v.resize(k);
  cout << solve(0) << endl;
}