--- a/mk_jars	Sun Nov 08 03:08:31 2020 +0000
+++ b/mk_jars	Sun Nov 08 13:09:38 2020 +0000
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 set -e
 
 subdirs=${1:-"pre_solution1 pre_solution2 pre_solution3 pre_solution4 main_solution1 main_solution2 main_solution3 main_solution4 main_solution5"}