diff --git a/README.md b/README.md
index 9ec43e7..f49575b 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@
 
 A curated collection of idiomatic design & application patterns for Go language.
 
-#### a fork of [tmrts/go-patterns](https://github.com/tmrts/go-patterns) but merged in with other awesome forks. can go with [patterns-in-examples](https://github.com/crazybber/go-fucking-patterns)
+#### a fork of [tmrts/go-patterns](https://github.com/tmrts/go-patterns) but merged in with other awesome forks. can go with [patterns-in-examples](https://github.com/crazybber/go-pattern-examples)
 
 
 ## Merged Repos
@@ -123,4 +123,4 @@ A curated collection of idiomatic design & application patterns for Go language.
 
 ## A pattern implementation
 
-[go-patterns-in-examples](https://github.com/crazybber/go-fucking-patterns)
+[go-patterns-in-examples](https://github.com/crazybber/go-pattern-examples)
diff --git a/playground/singleton/internal/singleton.go b/creational/singleton/singleton/internal/singleton.go
similarity index 100%
rename from playground/singleton/internal/singleton.go
rename to creational/singleton/singleton/internal/singleton.go
diff --git a/playground/singleton/main.go b/creational/singleton/singleton/main.go
similarity index 100%
rename from playground/singleton/main.go
rename to creational/singleton/singleton/main.go
diff --git a/profiling/profile.go b/profiling/profile.go
index 7b615c6..d0ad946 100644
--- a/profiling/profile.go
+++ b/profiling/profile.go
@@ -18,8 +18,8 @@ func BigIntFactorial(x big.Int) *big.Int {
 	defer Duration(time.Now(), "IntFactorial")
 
 	y := big.NewInt(1)
-	for one := big.NewInt(1); x.Sign() > 0; x.Sub(x, one) {
-		y.Mul(y, x)
+	for one := big.NewInt(1); x.Sign() > 0; x.Sub(&x, one) {
+		y.Mul(y, &x)
 	}
 
 	return x.Set(y)