package main

import (
	"math"
	"sort"
)

// r =1 , s = 12 , r = 2 , s = 12 + 24 = 36 , r = 3 , s = 12 + 24 + 36 = 72 , r = 4 , s  = 12 + 24 + 36 + 48 = (a1 + an) * n / 2 = a1*(n+1)*n/2
func minimumPerimeter(neededApples int64) int64 {
	maxNum := math.Sqrt(math.Sqrt(1e15 / 3))
	return int64(sort.Search(int(maxNum), func(x int) bool {
		num := 0
		for x >= 1 {
			num += 12 * x * x
			x--
		}
		return num >= int(neededApples)
	}) * 8)
}