diff --git a/iota.go b/iota.go
new file mode 100644
index 0000000..e308bed
--- /dev/null
+++ b/iota.go
@@ -0,0 +1,41 @@
+package main
+
+import "fmt"
+
+// enum的な
+type Weekday int64
+const (
+	Sunday Weekday = iota // 0はじまり
+	Monday // 1
+	Tuesday // 2
+	Wednesday // 3
+	Thursday // 4
+	Friday // 5
+	Saturday // 6
+)
+
+const (
+	_ = 1 << (10 * iota) // 1 << (10 * 0)
+	KiB // 1 << (10 * 1)
+	MiB // 1 << (10 * 2)
+	GiB // 1 << (10 * 3)
+	TiB // 1 << (10 * 4)
+)
+
+func main() {
+	// 0 1 2 3 4 5 6
+	fmt.Printf("%d %d %d %d %d %d %d\n",
+		Sunday,
+		Monday,
+		Tuesday,
+		Wednesday,
+		Thursday,
+		Friday,
+		Saturday)
+	// 1024 1048576 1073741824 1099511627776
+	fmt.Printf("%d %d %d %d\n",
+		KiB,
+		MiB,
+		GiB,
+		TiB)
+}