UVa 694 - The Collatz Sequence

#include<stdio.h>
int main()
{
long long n, m, term, i, num=1;
scanf("%lld%lld", &n, &m);
while(n>=0 || m>=0)
{
term=1;
i=n;
while(i<=m && i!=1)
{
if (i%2 == 0)
{
i/=2;
}
else
{
i=3*i+1;
if (i>m)
break;
}
term++;
}
printf("Case %lld: A = %lld, limit = %lld, number of terms = %lld\n", num++, n, m, term);
scanf("%lld%lld", &n, &m);
}
return 0;
}