func minAvgTwoSlice(a []int) int {
	idx := 0
	min := float64(a[0]+a[1]) / 2

	for i := 0; i < len(a)-1; i++ {
		cur := float64(a[i]+a[i+1]) / 2
		if i+2 < len(a) {
			three := float64(a[i]+a[i+1]+a[i+2]) / 3
			if three < cur {
				cur = three
			}
		}
		if cur < min {
			min = cur
			idx = i
		}
	}

	return idx
}