19107번 - Jacana Numbers 다국어

Let us define Jacana numbers in the following way:

$$\begin{eqnarray*} J (n, 1) & = & n \text{,} \\ J (n, k) & = & n^{J (n, k - 1)} \text{ for $k > 1$.} \\ \end{eqnarray*} $$

We have two Jacana numbers: $J (n, a)$ and $J (m, b)$. Your task is to compare them.

The first line of input contains an integer $T$, the number of test cases ($1 \le T \le 10^4$).

Each test case contains four integers: $n$, $a$, $m$, and $b$ ($1 \le n, a, m, b \le 10^9$).

For each test case, print a single line containing a single character:

• if $J (n, a) > J (m, b)$, output ">",
• if $J (n, a) = J (m, b)$, output "="', and
• if $J (n, a) < J (m, b)$, output "<".