public static int[] primeFactor() {
		int[] arr = new int[21];
		int temp;
		for (int i = 2; i <= 20; i++) {
			temp = i;
			for (int a = 2; a <= i; a++) {
				if (temp % a == 0) {
					for (int z = 1; z <= 20; z++) {
						if (temp % Math.pow(a, z) == 0)
							arr[a] = Math.max(arr[a], z);
					}
				}
			}
		}
		arr[1] = 0;
		arr[4] = 0;
		arr[6] = 0;
		arr[8] = 0;
		arr[9] = 0;
		arr[10] = 0;
		arr[12] = 0;
		arr[14] = 0;
		arr[15] = 0;
		arr[16] = 0;
		arr[18] = 0;
		arr[20] = 0;
		return arr;
	}