main() {
	a, b := f(5)
	assert a == 0
	assert b == 5

	a, b = f(15)
	assert a == 1
	assert b == 5

	a, b = f(25)
	assert a == 2
	assert b == 5
}

f(b int) -> (int, int) {
	a := 0

	if b >= 10 {
		a, b = b / 10
	}

	return a, b
}