public class Main {
    public static void main(String[] args) {
        int[] ns = { 1, 4, 9, 16, 25 };
        for (int i=ns.length-1; i>=0; i--) {
            System.out.println(ns[i]);
        }
    }
}

public class Main {
    public static void main(String[] args) {
        int[] ns = { 1, 4, 9, 16, 25 };
        int sum = 0;
        for (int n: ns) {
            sum += n;
        }
        System.out.println(sum); // 55
    }
}

public class Main {
    public static void main(String[] args) {
        double pi = 0;
        int flag = 1;
        for (int i=1; i<10000000; i=i+2) {
            pi = pi + flag * (1.0 / i);
            flag = -flag;
        }
        pi = 4 * pi;
        System.out.println(pi);
    }
}