코드업(CodeUp) 4726 : 수열

import java.util.Arrays;
import java.util.ArrayList;
import java.util.Scanner;

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

        int n = sc.nextInt();
        int k = sc.nextInt();
        int[] tems = new int[n];

        for(int i = 0; i < n; i++) {
            tems[i] = sc.nextInt();
        }

        ArrayList<Integer> sums = new ArrayList<Integer>();

        int i = 0;
        int j = 0;
        while(j < n) {
            int sum = 0;
            for(j = i; j < i + k; j++) {
                sum += tems[j];
            }

            i++;
            sums.add(sum);
        }

        Integer[] rs = sums.toArray(new Integer[0]);
        Arrays.sort(rs);
        System.out.println(rs[rs.length - 1]);
    }
}