#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-9;
const int INFMEM = 63;
const int INF = 1061109567;
const long long LINF = 4557430888798830399LL;
const double DINF = numeric_limits<double>::infinity();
const long long MOD = 1000000007;
const int dx[8] = {1, 0, -1, 0, 1, 1, -1, -1};
const int dy[8] = {0, 1, 0, -1, 1, -1, 1, -1};
const double PI = 3.141592653589793;
inline void fastll(long long &input_number) {
  input_number = 0;
  int ch = getchar_unlocked();
  int sign = 1;
  while (ch < '0' || ch > '9') {
    if (ch == '-') sign = -1;
    ch = getchar_unlocked();
  }
  while (ch >= '0' && ch <= '9') {
    input_number = (input_number << 3) + (input_number << 1) + ch - '0';
    ch = getchar_unlocked();
  }
  input_number *= sign;
}
inline void open(string a) {
  freopen((a + ".in").c_str(), "r", stdin);
  freopen((a + ".out").c_str(), "w", stdout);
}
inline void fasterios() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
}
struct dt {
  long long val, idx;
};
long long n, k, x;
long long isi[5005];
deque<dt> antri;
long long memo[5005][5005];
int main() {
  cin >> n >> k >> x;
  for (int i = 1; i <= n; i++) {
    cin >> isi[i];
  }
  memset(memo, -63, sizeof(memo));
  memo[0][0] = 0;
  for (int i = 1; i <= n; i++) {
    antri.clear();
    antri.push_back({0, 0});
    for (int j = 1; j <= x; j++) {
      for (int l = max(0LL, i - k); l < i; l++) {
        memo[i][j] = max(memo[i][j], memo[l][j - 1] + isi[i]);
      }
    }
  }
  long long ans = -1;
  for (int i = (n - k + 1); i <= n; i++) {
    ans = max(ans, memo[i][x]);
  }
  cout << ans << '\n';
  return 0;
}
