Problem:
Score : 200 points

Problem Statement

A sequence a=\{a_1,a_2,a_3,......\} is determined as follows:

The first term s is given as input.

Let f(n) be the following function: f(n) = n/2 if n is even, and f(n) = 3n+1 if n is odd.

a_i = s when i = 1, and a_i = f(a_{i-1}) when i > 1.

Find the minimum integer m that satisfies the following condition:

There exists an integer n such that a_m = a_n (m > n).

Constraints

1 \leq s \leq 100

All values in input are integers.

It is guaranteed that all elements in a and the minimum m that satisfies the condition are at most 1000000.

Input

Input is given from Standard Input in the following format:

s

Output

Print the minimum integer m that satisfies the condition.

Sample Input 1

8

Sample Output 1

5

a=\{8,4,2,1,4,2,1,4,2,1,......\}. As a_5=a_2, the answer is 5.

Sample Input 2

7

Sample Output 2

18

a=\{7,22,11,34,17,52,26,13,40,20,10,5,16,8,4,2,1,4,2,1,......\}.

Sample Input 3

54

Sample Output 3

114

Solution in Go (1.6) (judge verdict: Wrong Answer)

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)

func getInt() int {
	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())
	return n
}

func getFloat() float64 {
	sc.Scan()
	n, _ := strconv.ParseFloat(sc.Text(), 64)
	return n
}

func sum(n []int) int {
	a := 0
	for _, v := range n {
		a += v
	}
	return a
}

func main() {
	sc.Split(bufio.ScanWords)
	s := getInt()

	var a []int
	m := make(map[int]int, 1)
	var ans int
	a = append(a, s)
	for i := 1; i > 0; i++ {
		if a[i-1]%2 == 0 {
			a = append(a, a[i-1]/2)
			m[a[i]]++
		} else {
			a = append(a, (3*a[i-1])+1)
			m[a[i]]++
		}

		if m[a[i]] == 2 {
			ans = i
			i = -1
		}
	}
	fmt.Println(ans + 1)
}