78nVC5 - Online Java Compiler & Debugging Tool

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();
        int k = sc.nextInt();

        long[] a = new long[n + 1];
        for (int i = 1; i <= n; i++) {
            a[i] = sc.nextLong();
        }

        long[][] dp = new long[n + 1][k + 1];
        long NEG_INF = Long.MIN_VALUE / 4;

        for (int i = 0; i <= n; i++) {
            Arrays.fill(dp[i], NEG_INF);
        }

        dp[1][1] = a[1];
        dp[1][0] = 0;
        dp[2][0] = 0;
        dp[2][1] = Math.max(a[1], a[2]);

        for (int i = 3; i <= n; i++) {
            dp[i][0] = 0;

            for (int j = 1; j <= k; j++) {
                dp[i][j] = Math.max(
                    dp[i - 1][j],
                    a[i] + dp[i - 2][j - 1]
                );
            }
        }

        System.out.println(dp[n][k]);
        sc.close();
    }
}