UVa 694 The Collatz Sequence Solution

#include<stdio.h>
int main()
{
long long a,b,c,i,j=1;
while(scanf("%lld%lld",&b,&c)==2)
{
if(b<0 && c<0)
break;
a=b;
for(i=1;i!=0;i++)
    {
    if(a==1)
    break;
    if(a%2==0)
    a=a/2;
    else
    a=a*3+1;
    if(a>c)
    break;
    }

printf("Case %lld: A = %lld, limit = %lld, number of terms = %lld\n",j,b,c,i);
j++;
}
}