First tell it how many strands each of your braids will have.
Then enter braids as strings of non-zero integers separated by spaces.
An integer n will represent the positive crossing of the nth strand over the n+1-st strand.
A negative integer -n will represent the "negative" crossing of the n+1-sts strand over the nth strand.
Notice that the absolute values of the numbers you enter have to be less than the number of strands, or you'll break it!
Also, if you put more than 16 strands in the braids, that'll probably break it too!
The output braids are given in terms of the standard Artin generators for the braid groups.