main() { f(1, 2, 3, 4, 5, 6) } f(a, b, c, d, e, f) { return g(f, e, d, c, b, a) } g(a, b, c, d, e, f) { assert a == 6 assert b == 5 assert c == 4 assert d == 3 assert e == 2 assert f == 1 }