func simple_moving_average(period) {

    var list = []
    var sum = 0

    func (number) {
        list.append(number)
        sum += number
        if (list.len > period) {
            sum -= list.shift
        }
        (sum / list.length)
    }
}

var ma3 = simple_moving_average(3)
var ma5 = simple_moving_average(5)

for num (1..5, flip(1..5)) {
  printf("Next number = %d, SMA_3 = %.3f, SMA_5 = %.1f\n",
    num, ma3.call(num), ma5.call(num))
}