#include <bits/stdc++.h>
using namespace std;
const int N = 152;
int f[N][N * N];
int ans, n, K, s;
void cc(int &x, const int &y) {
  if (x == -1 || x > y) x = y;
}
int main() {
  int i, j, k, x;
  scanf("%d%d%d", &n, &K, &s);
  memset(f, -1, sizeof(f));
  for (i = 0; i < N * N; ++i) f[0][i] = 0;
  for (i = 1; i <= n; ++i) {
    scanf("%d", &x);
    f[i][0] = f[i - 1][0] + x;
    for (j = i; j >= 1; --j)
      for (k = 1; k <= n * n; ++k) {
        if (k > 0 && f[j][k - 1] != -1) cc(f[j][k], f[j][k - 1]);
        if (k >= i - j && f[j - 1][k - i + j] != -1)
          cc(f[j][k], f[j - 1][k - i + j] + x);
      }
  }
  s = min(s, n * n);
  cout << f[K][s] << endl;
  return 0;
}
