#include <bits/stdc++.h>
using namespace std;
const double EPS = 1E-10;
inline int cmp(double x, double y = 0, double tol = EPS) {
  return (x <= y + tol) ? (x + tol < y) ? -1 : 0 : 1;
}
long long dp[5050][5050];
int main() {
  cin.tie(0);
  cout.tie(0);
  ios::sync_with_stdio(0);
  int n, m, k;
  cin >> n >> m >> k;
  vector<long long> a(n + 1, 0);
  for (int i = 1; i <= n; i++) cin >> a[i], a[i] += a[i - 1];
  memset(dp, -1, sizeof(dp));
  function<long long(int, int)> go = [&](int p, int l) {
    if (p > n || l == k) return 0LL;
    long long &ret = dp[p][l];
    if (ret != -1) return ret;
    ret = a[p + m - 1] - a[p - 1] + go(p + m, l + 1);
    if (p <= n - (k - l) * m) ret = max(ret, go(p + 1, l));
    return ret;
  };
  cout << go(1, 0);
  return 0;
}
