There are multiple cases.
For each case, there is one line of two integers $L$ and $R$, separated by single space.
Here are some analyses about sample cases.
For the first case, pouring $1$ unit into one cup will satisfy Alice.
For the second case, it is clearly that you cannot only pour once to reach the desired balance, but she can achieve it by pouring twice.
First you pour $1.5$ units into one cup, then you attempt to pour another $1.5$ units into the other cup.
Since the lower bound is $2$, at least $0.5$ unit remains in the pot after the first pouring.
If the initial volume is in range $[2, 3]$, the second cup will have volume in range $[0.5, 1.5]$ which is balanced with $1.5$ unit in the first cup, and at most $1$ unit remain after these two attempts.
About $1000$ test cases, and $0 \le L \le R \le 10^{16}$.