diff --git a/2013/distsys/addr1.go b/2013/distsys/addr1.go
index eec6605..7ff3986 100644
--- a/2013/distsys/addr1.go
+++ b/2013/distsys/addr1.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/distsys/addr2.go b/2013/distsys/addr2.go
index 2f4c3e3..9a307ef 100644
--- a/2013/distsys/addr2.go
+++ b/2013/distsys/addr2.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/distsys/addr3.go b/2013/distsys/addr3.go
index b1a1c5c..9c1c293 100644
--- a/2013/distsys/addr3.go
+++ b/2013/distsys/addr3.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/distsys/addr4.go b/2013/distsys/addr4.go
index 5c6bb9e..fb7bdb4 100644
--- a/2013/distsys/addr4.go
+++ b/2013/distsys/addr4.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/distsys/addr5.go b/2013/distsys/addr5.go
index 159f9cc..4287499 100644
--- a/2013/distsys/addr5.go
+++ b/2013/distsys/addr5.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/distsys/finger.go b/2013/distsys/finger.go
index f1fd110..de305fc 100644
--- a/2013/distsys/finger.go
+++ b/2013/distsys/finger.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/distsys/hello.go b/2013/distsys/hello.go
index e7b4c83..6e52b38 100644
--- a/2013/distsys/hello.go
+++ b/2013/distsys/hello.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import "fmt"
diff --git a/2013/distsys/hello0.go b/2013/distsys/hello0.go
index c2fbf9c..55a2c1b 100644
--- a/2013/distsys/hello0.go
+++ b/2013/distsys/hello0.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import "fmt"
diff --git a/2013/distsys/hello1.go b/2013/distsys/hello1.go
index 4b560f3..31475f2 100644
--- a/2013/distsys/hello1.go
+++ b/2013/distsys/hello1.go
@@ -1,7 +1,10 @@
+// +build OMIT
+
 package main
 
 import (
 	"flag"
+
 	"github.com/golang/glog"
 )
 
diff --git a/2013/distsys/replread.go b/2013/distsys/replread.go
index aae6dbe..911ba50 100644
--- a/2013/distsys/replread.go
+++ b/2013/distsys/replread.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/distsys/replwrite.go b/2013/distsys/replwrite.go
index a91603f..3d48603 100644
--- a/2013/distsys/replwrite.go
+++ b/2013/distsys/replwrite.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/distsys/writebuffer.go b/2013/distsys/writebuffer.go
index 0f00a9c..8ac1c7a 100644
--- a/2013/distsys/writebuffer.go
+++ b/2013/distsys/writebuffer.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/distsys/writebuffer2.go b/2013/distsys/writebuffer2.go
index 90d9d5a..3dba109 100644
--- a/2013/distsys/writebuffer2.go
+++ b/2013/distsys/writebuffer2.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/go-sreops/goroutines-channels.go b/2013/go-sreops/goroutines-channels.go
index 61ac79a..a2346d6 100644
--- a/2013/go-sreops/goroutines-channels.go
+++ b/2013/go-sreops/goroutines-channels.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/go-sreops/goroutines.go b/2013/go-sreops/goroutines.go
index be97189..17e0c2d 100644
--- a/2013/go-sreops/goroutines.go
+++ b/2013/go-sreops/goroutines.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/go-sreops/hello.go b/2013/go-sreops/hello.go
index f7ab034..adaeee1 100644
--- a/2013/go-sreops/hello.go
+++ b/2013/go-sreops/hello.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/go4python/deco.go b/2013/go4python/deco.go
index b589a26..3b5bd79 100644
--- a/2013/go4python/deco.go
+++ b/2013/go4python/deco.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/go4python/decoex.go b/2013/go4python/decoex.go
index 42725db..77ad544 100644
--- a/2013/go4python/decoex.go
+++ b/2013/go4python/decoex.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/go4python/fib-gen.go b/2013/go4python/fib-gen.go
index 5142cc7..29d189e 100644
--- a/2013/go4python/fib-gen.go
+++ b/2013/go4python/fib-gen.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import "fmt"
diff --git a/2013/go4python/fib-gen2.go b/2013/go4python/fib-gen2.go
index 9625ba1..f3df3c2 100644
--- a/2013/go4python/fib-gen2.go
+++ b/2013/go4python/fib-gen2.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import "fmt"
diff --git a/2013/go4python/fib.go b/2013/go4python/fib.go
index dbfef11..2c0547f 100644
--- a/2013/go4python/fib.go
+++ b/2013/go4python/fib.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import "fmt"
diff --git a/2013/go4python/genex.go b/2013/go4python/genex.go
index 6914d5f..9ee48a6 100644
--- a/2013/go4python/genex.go
+++ b/2013/go4python/genex.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import "fmt"
diff --git a/2013/go4python/genex2.go b/2013/go4python/genex2.go
index 50daa06..1b46509 100644
--- a/2013/go4python/genex2.go
+++ b/2013/go4python/genex2.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import "fmt"
diff --git a/2013/go4python/monkey.go b/2013/go4python/monkey.go
index 161180a..dfcd61d 100644
--- a/2013/go4python/monkey.go
+++ b/2013/go4python/monkey.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (
diff --git a/2013/go4python/typesandmethods.go b/2013/go4python/typesandmethods.go
index 53bc1e2..fa7d5da 100644
--- a/2013/go4python/typesandmethods.go
+++ b/2013/go4python/typesandmethods.go
@@ -1,3 +1,5 @@
+// +build OMIT
+
 package main
 
 import (