class Main {
  public static void main(String[] args) {
    int a[] = {1,2,3,7,4,8,1,8,1,9,10,2,5,2,3};
    int sum = 0;
    for (int i=0;i<a.length; i++) {
      sum += a[i];
    }
    System.out.println(maxPlayer1(a, 0, sum, 0, a.length));
  }
  public static int maxPlayer1(int[] a, int currSum, int sum, int start, int len) {
    if (len-start <=3) {
      int val = 0;
      for (int i=start; i<len; i++) {
        val += a[i];
      }
      return val;
    }

    int v1 = a[start] + (sum - currSum - a[start]) -
    maxPlayer1(a, currSum + a[start], sum, start + 1, a.length);

    int v2 = a[start] + a[start+1] + (sum - currSum - a[start] - a[start+1]) -
    maxPlayer1(a, currSum + a[start] + a[start+1], sum, start + 2, a.length);

    int v3 = a[start] + a[start+1] + a[start+2] + (sum - currSum - a[start] - a[start+1] - a[start+2]) -
    maxPlayer1(a, currSum + a[start] + a[start+1] + a[start+2], sum, start + 3, a.length);

    return Math.max(v1, Math.max(v2, v3));
  }
}