diff --git a/stack/stack.go b/stack/stack.go
index 1c7b22d..cc878fe 100644
--- a/stack/stack.go
+++ b/stack/stack.go
@@ -1,61 +1,61 @@
 package stack
 
 type Stack struct {
-    st []interface{}
-    len int
+	st  []interface{}
+	len int
 }
 
 func New() *Stack {
-    stack := &Stack{}
-    stack.st = make([]interface{}, 1)
-    stack.len = 0
-    return stack
+	stack := &Stack{}
+	stack.st = make([]interface{}, 1)
+	stack.len = 0
+	return stack
 }
 
 func (stack *Stack) Length() int {
-    return stack.len
+	return stack.len
 }
 
 func (stack *Stack) Pop() {
-    stack.st = stack.st[1:]
-    stack.len -= 1
+	stack.st = stack.st[1:]
+	stack.len -= 1
 }
 
 func (stack *Stack) Peek() interface{} {
-    return stack.st[0]
+	return stack.st[0]
 }
 
 func (stack *Stack) IsEmpty() bool {
-    return (stack.len == 0)
+	return (stack.len == 0)
 }
 
 func (stack *Stack) Push(value interface{}) {
-    add(stack, value)
-} 
+	add(stack, value)
+}
 
 func add(slice *Stack, value interface{}) {
-    slice.len += 1
-    var tmpSlice []interface{} = make([]interface{}, slice.len)
-    if slice.len == 0 {
-        slice.st[0] = value
-        return
-    }
-    
-    for i:=0; i < slice.len; i++ {
-        tmpSlice[i] = 0
-    }
-    
-    for i:=0; i < slice.len; i++ {
-        if i == 0 {
-            tmpSlice[0] = value
-        } else {
-            tmpSlice[i] = slice.st[i - 1]
-        }
-
-        if i == slice.len - 1 {
-            break
-        }
-    }
-    
-    slice.st = tmpSlice
+	slice.len += 1
+	var tmpSlice []interface{} = make([]interface{}, slice.len)
+	if slice.len == 0 {
+		slice.st[0] = value
+		return
+	}
+
+	for i := 0; i < slice.len; i++ {
+		tmpSlice[i] = 0
+	}
+
+	for i := 0; i < slice.len; i++ {
+		if i == 0 {
+			tmpSlice[0] = value
+		} else {
+			tmpSlice[i] = slice.st[i-1]
+		}
+
+		if i == slice.len-1 {
+			break
+		}
+	}
+
+	slice.st = tmpSlice
 }
diff --git a/stack/stack_test.go b/stack/stack_test.go
index f5c87fd..eee4749 100644
--- a/stack/stack_test.go
+++ b/stack/stack_test.go
@@ -3,23 +3,23 @@ package stack
 import "testing"
 
 func Test_Stack(t *testing.T) {
-    stack := New()
+	stack := New()
 
-    stack.Push(5)
-    stack.Push(6)
-    stack.Push(7)
-    
-    if stack.Length() != 3 {
-        t.Error("[Error] stack length is wrong")
-    }
+	stack.Push(5)
+	stack.Push(6)
+	stack.Push(7)
 
-    stack.Pop()
+	if stack.Length() != 3 {
+		t.Error("[Error] stack length is wrong")
+	}
 
-    if stack.Length() != 2 {
-        t.Error("[Error] stack length is wrong after pop")
-    }
-    
-    if stack.Peek() != 6 {
-        t.Error("[Error] stack Peek is wrong")
-    }
+	stack.Pop()
+
+	if stack.Length() != 2 {
+		t.Error("[Error] stack length is wrong after pop")
+	}
+
+	if stack.Peek() != 6 {
+		t.Error("[Error] stack Peek is wrong")
+	}
 }