include oo~~~~

include

using namespace std;

int main() {

long long a = 0, n;
scanf("%lld", &n);
while (n != 1) {
	a++;
	if (n % 2 == 1)
		n = n * 3 + 1;
	else
		n /= 2;
}
if (a >= 300) {
	printf("-1");
	return 0;
}
printf("%lld", a);
return 0;

}