diff --git a/yearistype.sh b/yearistype.sh
index e69de29..6d1e487 100644
--- a/yearistype.sh
+++ b/yearistype.sh
@@ -0,0 +1,18 @@
+#! /bin/sh
+
+: '%W%'
+
+case $#-$2 in
+	2-odd)	case $1 in
+			*[13579])	exit 0 ;;
+			*)		exit 1 ;;
+		esac ;;
+	2-even)	case $1 in
+			*[24680])	exit 0 ;;
+			*)		exit 1 ;;
+		esac ;;
+	2-*)	echo "$0: wild type - $2" >&2
+		exit 1 ;;
+	*)	echo "$0: usage is $0 year type" >&2
+		exit 1 ;;
+esac