-bash-4.3$ ./reduce 40 166
40/166 reduces to 20/83
-bash-4.3$ ./reduce 8 2
8/2 reduces to 4
-bash-4.3$ ./reduce -4 24
-4/24 reduces to -1/6
-bash-4.3$ ./reduce 4 -24
4/-24 reduces to -1/6
-bash-4.3$ ./reduce -3 -15
-3/-15 reduces to 1/5
-bash-4.3$ ./reduce 2
usage: reduce numerator denominator
-bash-4.3$ ./reduce
usage: reduce numerator denominator