#include<bits/stdc++.h>
using namespace std;
long long n,s,ans=1;
int main(){
    cin>>n;
    s=n;
    if(n%10==3){
    	cout<<ans;
		return 0; 
	}
    while(1){
    	ans++;
    	if(n%2==0)n/=2,s+=n;
    	else if(n%2==1)n=n*3+1,s+=n;
    	if(s%10==3)break;
	}
	cout<<ans;
    return 0;
}

简单