r.go | 2 +-

diff --git a/r.go b/r.go
index 131f9029a3c20bc2457e9a5747d2045644e7b121ad9960453786b56b6d7ef160..a3b6bb0a974f0c467c02e422fdbec875aa20a05e8aaf68d264cd7b796c0f5998 100644
--- a/r.go
+++ b/r.go
@@ -48,7 +48,7 @@ 		('a' <= k[0] && k[0] <= 'z') ||
 		('A' <= k[0] && k[0] <= 'Z')) {
 		return "", ""
 	}
-	for _, c := range k {
+	for _, c := range k[1:] {
 		if !((c == '_') ||
 			('a' <= c && c <= 'z') ||
 			('A' <= c && c <= 'Z') ||