Farmer John has an integer $x$. He creates a sequence of length $n$ by alternating integers $x$ and $-x$, starting with $x$.

For example, if $n = 5$, the sequence looks like: $x, -x, x, -x, x$.

He asks you to find the sum of all integers in the sequence.

Input

The first line contains an integer $t$ ($1 \leq t \leq 100$)  — the number of test cases.

The only line of input for each test case is two integers $x$ and $n$ ($1 \leq x, n \leq 10$).

Output

For each test case, output the sum of all integers in the sequence.

Samples

4
1 4
2 5
3 6
4 7

0
2
0
4