UVA 694 : The Collatz Sequence -Solution

#include <stdio.h>

int main()
{
long long int A, limit, ncase=1, lenght,n;
while (scanf("%lld%lld",&A,&limit)==2)
{
if (A<0 && limit<0)
break;
n=A;
lenght=0;
while (n<=limit)
{
lenght++;
if (n==1)
break;
else if (n%2==0)
n=n/2;
else
n=3*n+1;
}
printf("Case %lld: A = %lld, limit = %lld, number of terms = %lld\n",ncase++,A,limit, lenght);
}
return 0;
}