Problem:
Score : 700 points

Problem Statement

We have N gemstones labeled 1 through N.

You can perform the following operation any number of times (possibly zero).

Select a positive integer x, and smash all the gems labeled with multiples of x.

Then, for each i, if the gem labeled i remains without getting smashed, you will receive a_i yen (the currency of Japan).
However, a_i may be negative, in which case you will be charged money.

By optimally performing the operation, how much yen can you earn?

Constraints

All input values are integers.

1 \leq N \leq 100

|a_i| \leq 10^9

Input

Input is given from Standard Input in the following format:

N
a_1 a_2 ... a_N

Output

Print the maximum amount of money that can be earned.

Sample Input 1

6
1 2 -6 4 5 3

Sample Output 1

12

It is optimal to smash Gem 3 and 6.

Sample Input 2

6
100 -100 -100 -100 100 -100

Sample Output 2

200

Sample Input 3

5
-1 -2 -3 -4 -5

Sample Output 3

0

It is optimal to smash all the gems.

Sample Input 4

2
-1000 100000

Sample Output 4

99000

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Main main = new Main();
		main.solveE();
	}

	private void solveE() {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int[] a = new int[N + 1];
		long sum = 0L;
		for (int i = 1; i <= N; i++) {
			a[i] = sc.nextInt();
			sum += a[i];
		}
		int min_x = -1;
		while (min_x != 0) {
			min_x = 0;
			long min = 0L;
			for (int x = 1; x <= 100; x++) {
				long tmp = 0L;
				for (int i = 1; i <= N; i++) {
					if (i % x == 0) {
						tmp += a[i];
					}
				}
				if (min > tmp) {
					min = tmp;
					min_x = x;
				}
			}
			if (min_x != 0) {
				for (int i = 1; i <= N; i++) {
					if (i % min_x == 0) {
						a[i] = 0;
					}
				}
				sum -= min;
			}
		}
		System.out.println(sum);
	}
}