I got WA just on testcase #10. Any ideas?

Here is my code:

int main() {
    fileio();
 
    cin >> n >> k;
    for (int i = 1; i <= n; i++) cin >> a[i];
 
    if (n == 1) {
        cout << 0;
        return 0;
    }
    dp[k] = 0;
    dp[k + 1] = a[k + 1];
    for (int i = k + 2; i <= n; i++)
        dp[i] = max(dp[i - 1], dp[i - 2]) + a[i];
 
    dp_[n] = dp[n];
    dp_[n - 1] = max(dp[n] + a[n - 1], dp[n - 1]);
    for (int i = n - 2; i >= 1; i--){
        if (i >= k) dp_[i] = max(dp[i], (max(dp_[i + 1], dp_[i + 2]) + a[i]));
        else dp_[i] = max(dp_[i + 1], dp_[i + 2]) + a[i];