diff --git a/2015/01/d1.pl b/2015/01/d1.pl
new file mode 100644
index 0000000..849c227
--- /dev/null
+++ b/2015/01/d1.pl
@@ -0,0 +1,4 @@
+use 5.20.0;
+
+say eval <> =~ s/\(/+1/gr =~ s/\)/-1/gr;
+
diff --git a/2015/01/d1b.pl b/2015/01/d1b.pl
new file mode 100644
index 0000000..5e4c1da
--- /dev/null
+++ b/2015/01/d1b.pl
@@ -0,0 +1,10 @@
+use 5.20.0;
+use List::AllUtils qw/ reduce /;
+
+my $i;
+reduce {
+    my $l = $a + ( $b eq '(' ? 1 : -1 );
+    $i++;
+    die $i if $l < 0;
+    $l;
+} 0, split '', <>;