diff --git a/README.md b/README.md
index 979a993..ae4e10b 100755
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
->In the begning when God created the heavens and the earth. the earth was a formless void and darkness covered the face of the deep, while a wind from God swept over the face of the waters. Then God said,"Let there be light"; and there was light. And God saw that the light was good; and God separated the light from the darkness. (GENESIS 1:1-4)
+# 注意：本书已经停止印刷，请学习者转到：《Python完全自学教程》中学习，这是一本开源免费的在线读物，地址：https://github.com/qiwsir/PythonBook
 
 # 《跟老齐学Python：轻松入门》
 
@@ -7,30 +7,3 @@
 ![](./python-book1.png)
 
 # 相关资源
-
-## 个人网站
-
-[itdiffer.com](http://www.itdiffer.com)
-
-## QQ群：26913719
-
-说明：此QQ群是读者交流，而非作者答疑区，请特别注意。如果读者有问题，可以在群里面跟其它读者交流。作者没有答疑的义务。恕不接待任何形式的答疑。
-
-关于本QQ群的更多说明：
-
-- 加入本群，收费1元，目的是免群主审核，并且拦住广告发布人。如果对此有异议，请不要加入。
-- 因为设置了上述功能，群主无法单独邀请用户加入了（这是QQ方面的规定），所以，不要让群主邀请。
-- 更不要通过其它途径给群主一块钱，然后让群主想办法把你加到群里，群主表示做不到。
-
-再次提醒：对入群收费1元，有异议者请不要加入。
-
-# 本书配套小程序
-
-小程序名称：跟老齐学
-
-<img src="https://raw.githubusercontent.com/qiwsir/DjangoPracticeProject/master/smallprogramming.jpg" width=200 height=200 />
-
-# Python学习资源推荐：
-
-- 系列图书《跟老齐学Python：Django实战》、《跟老齐学Python：数据分析》，各大网店和书店有售
-- 在线课程：[Python3入门和能力提升](https://www.cctalk.com/m/course/111302)
diff --git a/videolesson/arithmetic.py b/videolesson/arithmetic.py
new file mode 100644
index 0000000..b7f2ce5
--- /dev/null
+++ b/videolesson/arithmetic.py
@@ -0,0 +1,22 @@
+#coding:utf-8
+
+'''
+lesson 07-6
+filename: arithmetic.py
+'''
+
+print('Please input two int:')
+a = input('a number:')
+b = input('another number:')
+a = int(a)
+b = int(b)
+
+add_result = a + b
+sub_result = a - b
+mul_result = a * b
+div_result = a / b
+
+print(a, " + ", b, ' = ', add_result)
+print(a, " - ", b, ' = ', sub_result)
+print(a, " * ", b, ' = ', mul_result)
+print(a, " / ", b, ' = ', div_result)
\ No newline at end of file
diff --git a/videolesson/country.py b/videolesson/country.py
new file mode 100644
index 0000000..2e11dfc
--- /dev/null
+++ b/videolesson/country.py
@@ -0,0 +1,12 @@
+#coding:utf-8
+
+'''
+lesson 15-3
+filename: country.py
+'''
+
+country = {"CHINA": "BEIJING", 'CANADA': "OTTAWA", 'GREECE': 'ATHENS', 'ITALY': 'ROME'}
+
+name = input("input the name of country:")
+capital = country[name]
+print(name, "-->", capital)
\ No newline at end of file
diff --git a/videolesson/judge_input.py b/videolesson/judge_input.py
new file mode 100644
index 0000000..0c6a52f
--- /dev/null
+++ b/videolesson/judge_input.py
@@ -0,0 +1,13 @@
+#coding:utf-8
+'''
+    lesson 19-03
+    filename: judge_input.py
+'''
+input_char = input("Input something: ")
+if input_char.isdigit(): 
+    result = int(input_char) * 10
+    print("You input {0}. Output is {1}".format(input_char, result))
+elif input_char.isalpha(): 
+    print(input_char + "@python")
+else: 
+    print(input_char)
\ No newline at end of file
diff --git a/videolesson/newton.py b/videolesson/newton.py
new file mode 100644
index 0000000..a35f0e3
--- /dev/null
+++ b/videolesson/newton.py
@@ -0,0 +1,12 @@
+#coding: utf-8
+'''
+    calculate the square root by Newton's method.
+    lesson 22-1
+    filename: newton.py
+'''
+value = 23 #f(x) = x^2 - 23 
+epsilon = 0.001
+result = value / 2
+while abs(result*result - value) >= epsilon:
+    result = result - ((result*result - value) / (2 * result))
+print("The square root of {0} is about {1}".format(value, result))
\ No newline at end of file
diff --git a/videolesson/odd_even.py b/videolesson/odd_even.py
new file mode 100644
index 0000000..f2f83f1
--- /dev/null
+++ b/videolesson/odd_even.py
@@ -0,0 +1,16 @@
+#coding:utf-8
+'''
+    lesson 19-04
+    filename: odd_even.py
+'''
+lst = [1,2,3,4,5,6,7,8,9,10]
+odd = []
+even = []
+for i in lst:
+    if i % 2 == 0:
+        even.append(i)
+    else:
+        odd.append(i)
+
+print("odd: ", odd)
+print("even: ", even)
\ No newline at end of file