diff --git a/lpst.pl b/lpst.pl
index a1ca691..61a7c33 100644
--- a/lpst.pl
+++ b/lpst.pl
@@ -468,7 +468,7 @@ sub calc_move($$){
     $x_shift = $mov->[0];
     
     # make adjustment
-    $ni = ($y_shift / ($y_shift * -1));
+    $ni = $y_shift != 0 ? ($y_shift / ($y_shift * -1)) : -1;
     $ni *= -1;
     
     $n0 = ($r0 + 1) % 2;
@@ -495,12 +495,12 @@ binmode(STDOUT, ":utf8");
 }(1...11);
 
 my $m1 = "F4";
-my $c1 = $MG_A;
+my $c1 = $MG_QS;
 
-$board{$m1} = $P1.$DIV.$c;
+$board{$m1} = $P1.$DIV.$c1;
 
-for my $mv in $MOVE{}
-printf("%s\n", calc_move($m1, [-2,-2]));
-# printf("%s\n", calc_move($m1, [-6,6]));
+for my $mv (@{$MOVE{$c1}}){
+    printf("%s\n", calc_move($m1, $mv));
+}
 disp_board();