1031.XXX定律

#include<iostream>
using namespace std;

int change(int x){
    if(x%2==0) return x/2;
    else return (3*x+1)/2; 
}

int main(){
    int n;
    while(cin>>n){
        if(n==0) break;
        int i=0;
        while(n!=1){
            n=change(n);
            i++;
        }
        cout<<i<<endl;
    }
    return 0;
}