刚学C语言，请用C语言解答一下

int main()
{                   
    int  n;
    scanf("%d",&n);
    int sum=0;
    while(n!=1){
        if(n%2==0)
            n/=2;
        else
            n=3*n+1;
        ++sum;
    }
    printf("%d\n",sum);
    return 0;    
}