static box TestBox {
  method fib(n) {
    local i = 0
    local a = 0
    local b = 1
        loop(i < n) {
      local t = a + b
            a = b
            b = t
            i = i + 1
        }
        return b
    }
}

static box Main {
  method main(args) {
    local t = new TestBox()
        return t.fib(6)
    }
}