diff --git a/class/calc.cpp b/class/calc.cpp
new file mode 100644
index 0000000..65fde69
--- /dev/null
+++ b/class/calc.cpp
@@ -0,0 +1,33 @@
+#include<iostream>
+#include<windows.h>
+
+using namespace std;
+
+/*
+int main(){
+    int range = 0;
+    while (range != 5)
+    {
+        int a,s;
+        cin >>a;
+
+        s = a * a;
+
+        cout <<"结果:"<<s<<endl;
+        range++;
+    }
+    
+    return 0;
+}*/
+
+int main(){
+    int time = 15;
+    while (time > 0)
+    {
+        cout <<"你还剩"<<time<<"分钟"<<endl;
+        Sleep(60000);
+        time--;
+    }
+    
+    return 0;
+}
\ No newline at end of file
diff --git a/homework_11.22(1).cpp b/homework_11.22(1).cpp
index 117028b..fb98a37 100644
--- a/homework_11.22(1).cpp
+++ b/homework_11.22(1).cpp
@@ -4,7 +4,9 @@
 using namespace std;
 
 int main(){
-    int tree = 17,wn = 0,clim = 3,down = 1,time = 0;
+    int tree,wn = 0,clim = 3,time = 0;
+
+    cin >> tree;
 
     while (wn < tree)
     {
@@ -16,11 +18,11 @@ int main(){
             break;
         }
         
-        wn -= down;
+        wn--;
         time++;
     }
 
-    cout <<time<<endl;
+    cout <<"需要"<<time<<" 分钟才能爬到树顶"<<endl;
     
     return 0;
 }
\ No newline at end of file
diff --git a/homework_laster.cpp b/homework_laster.cpp
index 00fdf5c..e69de29 100644
--- a/homework_laster.cpp
+++ b/homework_laster.cpp
@@ -1,42 +0,0 @@
-/*某邮局对邮寄包裹有如下规定:若包裹的重量超过30千克，则不予邮寄，对可以邮寄的包裹每件收取手续费0.2元，再加上根据以下收费标准计算的结果。收费标准(元/千克)
-重量(千克)
-重量<=100.8010<重量<=200.750.7
-20<重量<=30
-请编写一个程序，输入包裹重量，输出所需费用或“Fail”表示无法邮寄*/
-#include<iostream>
-#include<windows.h>
-#include<iomanip>
-
-using namespace std;
-
-int main(){
-    float CIN,money;
-
-    cin >>CIN;
-    
-    if (CIN <= 10)
-    {
-        money = CIN * 0.80 + 0.20;
-        cout <<fixed<<setprecision(2)<<money;
-        Sleep(2000);
-        return 0;
-    }else if (CIN > 10 and CIN <= 20)
-    {
-        money = CIN * 0.75 + 0.20;
-        cout <<fixed<<setprecision(2)<<money;
-        Sleep(2000);
-        return 0;
-    }else if (CIN > 20 and CIN <=30)
-    {
-        money = CIN * 0.7 + 0.20;
-        cout <<fixed<<setprecision(2)<<money;
-        Sleep(2000);
-        return 0;
-    }else
-    {
-        cout <<"Fail!";
-        Sleep(2000);
-        return 1;
-    }
-    return 0;
-}
\ No newline at end of file
diff --git a/old_homework/11.15.cpp b/old_homework/11.15.cpp
new file mode 100644
index 0000000..00fdf5c
--- /dev/null
+++ b/old_homework/11.15.cpp
@@ -0,0 +1,42 @@
+/*某邮局对邮寄包裹有如下规定:若包裹的重量超过30千克，则不予邮寄，对可以邮寄的包裹每件收取手续费0.2元，再加上根据以下收费标准计算的结果。收费标准(元/千克)
+重量(千克)
+重量<=100.8010<重量<=200.750.7
+20<重量<=30
+请编写一个程序，输入包裹重量，输出所需费用或“Fail”表示无法邮寄*/
+#include<iostream>
+#include<windows.h>
+#include<iomanip>
+
+using namespace std;
+
+int main(){
+    float CIN,money;
+
+    cin >>CIN;
+    
+    if (CIN <= 10)
+    {
+        money = CIN * 0.80 + 0.20;
+        cout <<fixed<<setprecision(2)<<money;
+        Sleep(2000);
+        return 0;
+    }else if (CIN > 10 and CIN <= 20)
+    {
+        money = CIN * 0.75 + 0.20;
+        cout <<fixed<<setprecision(2)<<money;
+        Sleep(2000);
+        return 0;
+    }else if (CIN > 20 and CIN <=30)
+    {
+        money = CIN * 0.7 + 0.20;
+        cout <<fixed<<setprecision(2)<<money;
+        Sleep(2000);
+        return 0;
+    }else
+    {
+        cout <<"Fail!";
+        Sleep(2000);
+        return 1;
+    }
+    return 0;
+}
\ No newline at end of file