diff --git a/NumTypeExer.py b/NumTypeExer.py
index ccf4290..b17be55 100644
--- a/NumTypeExer.py
+++ b/NumTypeExer.py
@@ -3,18 +3,20 @@
 import time
 
 print("贴贴我的百花酱！数字打字练习\n")
-print("程序会随机生成若干组0至99999999的整数，每输入一组按回车键继续；要结束练习，请输入-1并回车。")
+print("程序会随机生成若干组指定位数的整数，每输入一组按回车键继续；要结束练习，请输入-1并回车。")
 print("练习结束后会显示所用时间、完成数目和输入速度，并列出输入错误的数字。\n")
-input("按回车键开始：")
+num_len = int(input("请输入要生成的随机数位数，练习会立即开始："))
 
 wrongList = []
 sum = 0
 start_time = time.time()
 while True:
-    target = random.randint(0, 99999999)
+    target = ""
+    for i in range(num_len):
+        target = target + str(random.randint(0,9))
     print(str(target)+": ", end='')
-    answer = int(input())
-    if answer == -1:
+    answer = input()
+    if answer == "-1":
         break
     sum += 1
     if target != answer:
@@ -25,7 +27,7 @@
 print("\n错误列表：")
 print("正确答案\t你的输入")
 for wrongNum in wrongList:
-    print(str(wrongNum[0]) + "\t" + str(wrongNum[1]))
+    print(wrongNum[0] + "\t" + wrongNum[1])
 used_time = end_time - start_time
 print("\n练习" + str(sum) + "个，错误" + str(len(wrongList)) + "个，用时" + str(int(used_time)) + "秒，有效平均速度为每分钟" + str(format(float((sum-len(wrongList))/(used_time/60)), '.1f')) + "个。\n")
 
diff --git a/build.bat b/build.bat
new file mode 100644
index 0000000..5c6e362
--- /dev/null
+++ b/build.bat
@@ -0,0 +1,14 @@
+@title pyinstaller -F .\NumTypeExer.py
+@echo off
+
+if exist .\build (
+del /q .\build
+)
+if exist .\dist (
+del /q .\dist
+)
+if exist .\NumTypeExer.spec (
+del /q .\NumTypeExer.spec
+)
+
+pyinstaller -F .\NumTypeExer.py
\ No newline at end of file