#include <bits/stdc++.h>
using namespace std;
const long long maxn = 5010;
long long n, m, k, a[maxn], d[maxn][maxn], b[maxn];
int main() {
  cin >> n >> m >> k;
  for (long long i = 1; i <= n; ++i) cin >> a[i];
  for (long long i = n; i >= n - m + 1; i--) b[n - m + 1] += a[i];
  for (long long i = n - m; i >= 1; i--) b[i] = b[i + 1] + a[i] - a[i + m];
  d[1][n - m + 1] = b[n - m + 1];
  for (long long i = n - m; i >= 1; i--) d[1][i] = max(d[1][i + 1], b[i]);
  for (long long i = 2; i <= k; ++i) {
    for (long long j = n - i * m + 1; j >= 1; j--)
      d[i][j] = max(d[i][j], max(d[i][j + 1], b[j] + d[i - 1][j + m]));
  }
  cout << d[k][1];
  return 0;
}
