在JAVA中分别利用while，do-while以及for循环编写程序

请各位大大帮帮忙
分别利用上面三种循环计算S=1+3+5+7+省略号+1001

public class Main {
    public static void main(String[] args) {
        int index = 1, sum = 0;
        while (index <= 1001) {
            sum += index;
            index += 2;
        }
        System.out.println(sum);

        index = 1;
        sum = 0;
        do {
            sum += index;
            index += 2;
        } while (index <= 1001);
        System.out.println(sum);

        sum = 0;
        for (index = 1; index <= 1001; index += 2) {
            sum += index;
        }
        System.out.println(sum);
    }
}