system command $a 0, then for $s 0
system command $a 0, then for $s 1
system command $a 0, then for $s 2
system command $a 0, then for $s 3
system command $a 0, then for $s 4
system command $a 1, then for $s 0
system command $a 1, then for $s 1
system command $a 1, then for $s 2
.... and so on and so on.