#include <bits/stdc++.h>
using namespace std;
void dbg_out() { cerr << endl; }
template <typename Head, typename... Tail>
void dbg_out(Head H, Tail... T) {
  cerr << ' ' << H;
  dbg_out(T...);
}
const long long MXN = 1e5 + 5, INF = 1e17;
void solve() {
  long long N, M, K;
  cin >> N >> M >> K;
  vector<long long> A(N + 1, 0);
  for (long long i = 1; i <= N; i++) {
    cin >> A[i];
    A[i] += A[i - 1];
  }
  vector<vector<long long>> dp(K + 1, vector<long long>(N + 1, -INF));
  for (long long j = 0; j <= N; j++) dp[0][j] = 0;
  for (long long i = 1; i <= K; i++) {
    for (long long j = 1; j <= N; j++) {
      if (j - M + 1 <= 0) continue;
      dp[i][j] = max(A[j] - A[j - M] + dp[i - 1][j - M], dp[i][j - 1]);
    }
  }
  cout << dp[K][N];
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  long long TC = 1;
  while (TC--) solve();
}
