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 C (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>

#define MAX 1000000

int main()
{
	int s;
	scanf("%d", &s);

	int tmp[MAX];
	int i, j, flag = 0;
	for (i = 0; i < MAX; i++)
		tmp[i] = 0;

	for (i = 0; i < MAX; i++) {
		if (i == 0) {
			tmp[i] = s;
		} else {
			if (tmp[i-1] % 2 == 0) {
				tmp[i] = tmp[i-1] / 2;
			} else {
				tmp[i] = 3 * tmp[i-1] + 1;
			}
		}
	}

	for (i = 0; i < MAX; i++) {
		for (j = i + 1; j < MAX; j++) {
			if (tmp[i] == tmp[j]) {
				flag = 1;
				break;
			}
		}
		if (flag == 1) {
			break;
		}
	}

	printf("%d\n", j+1);

	return 0;
}