The first line of the input contains an integer $T$, denoting the number of test cases.
In every test case, there are two integers $n$ and $m$ in the first line, denoting the number of the countries and the number of the flights.
Then there are $m$ lines, each line contains three integers $u_i$, $v_i$ and $w_i$, describing a flight.
$1\leq T\leq 20$.
$1\leq n\leq 16$.
$1\leq m\leq 100000$.
$1\leq w_i\leq 100$.
$1\leq u_i, v_i \leq n$.