public class Merge {
    public static int[] merge(int[] a, int[] b) {
        int[] c = new int[a.length + b.length];

        for (int i = 0; i < a.length; i++) {
            c[i] = a[i];
        }
        for (int i = 0; i < b.length; i++) {
            c[i + a.length] = b[i];
        }

        return c;
    }

    public static int[] merge3(int[] a, int[] b, int[] c) {
        return merge(merge(a,b),c);
    }
}