diff --git a/2015_sort_3num/Readme.md b/2015_sort_3num/Readme.md
new file mode 100644
index 0000000..b4f8d75
--- /dev/null
+++ b/2015_sort_3num/Readme.md
@@ -0,0 +1,3 @@
+# 标题
+
+* 内容
\ No newline at end of file
diff --git a/2015_sort_3num/doc/Readme.md b/2015_sort_3num/doc/Readme.md
new file mode 100644
index 0000000..4e768b5
--- /dev/null
+++ b/2015_sort_3num/doc/Readme.md
@@ -0,0 +1 @@
+# 
\ No newline at end of file
diff --git a/2015_sort_3num/doc/涓夊厓鎺掑簭.pdf b/2015_sort_3num/doc/涓夊厓鎺掑簭.pdf
new file mode 100644
index 0000000..161ed3f
Binary files /dev/null and b/2015_sort_3num/doc/涓夊厓鎺掑簭.pdf differ
diff --git a/2015_sort_3num/main.cpp b/2015_sort_3num/main.cpp
new file mode 100644
index 0000000..d103d65
--- /dev/null
+++ b/2015_sort_3num/main.cpp
@@ -0,0 +1,36 @@
+#include <iostream>
+using namespace std;
+int main()
+{
+    int n,a[100001],yi=0,er=0,ans=0;
+    cin>>n;
+    for(int i=1;i<=n;i++){
+        cin>>a[i];
+        if(a[i]==1){
+            yi++;
+        }
+        if(a[i]==2){
+            er++;
+        }
+    }
+    int per=0;
+    for(int i=1;i<=yi;i++){
+        if(a[i]!=1){
+            ans++;
+            if(a[i]==2){
+                per++;
+            }
+        }
+    }
+    for(int i=yi+1;i<=er+yi;i++){
+        if(a[i]!=2){
+            ans++;
+            if(a[i]==1&&per>0){
+                per--;
+                ans--;
+            }
+        }
+    }
+    cout<<ans;
+    return 0;
+}
diff --git a/2015_sort_3num/main.exe b/2015_sort_3num/main.exe
new file mode 100644
index 0000000..189a349
Binary files /dev/null and b/2015_sort_3num/main.exe differ
diff --git a/2015_sort_3num/test/in.txt b/2015_sort_3num/test/in.txt
new file mode 100644
index 0000000..e87671a
--- /dev/null
+++ b/2015_sort_3num/test/in.txt
@@ -0,0 +1,10 @@
+9
+2
+2
+1
+3
+3
+3
+2
+3
+1
\ No newline at end of file
diff --git a/2015_sort_3num/test/in2.txt b/2015_sort_3num/test/in2.txt
new file mode 100644
index 0000000..8ade25c
--- /dev/null
+++ b/2015_sort_3num/test/in2.txt
@@ -0,0 +1,11 @@
+10
+3
+3
+3
+2
+1
+2
+3
+2
+1
+3
\ No newline at end of file
diff --git a/2015_sort_3num/test/in3.txt b/2015_sort_3num/test/in3.txt
new file mode 100644
index 0000000..cf3045c
--- /dev/null
+++ b/2015_sort_3num/test/in3.txt
@@ -0,0 +1,2 @@
+1
+1
\ No newline at end of file
diff --git a/2015_sort_3num/test/out.txt b/2015_sort_3num/test/out.txt
new file mode 100644
index 0000000..6e9fc7d
--- /dev/null
+++ b/2015_sort_3num/test/out.txt
@@ -0,0 +1,18 @@
+## z:\Chao\src\2015_sort_3num\test\in.txt 
+2020/06/13 周六 10:23:28.60 
+4
+-----------------------------------------------
+Process exited after 150 ms with return value 0
+
+## z:\Chao\src\2015_sort_3num\test\in2.txt 
+2020/06/13 周六 10:23:28.60 
+4
+-----------------------------------------------
+Process exited after 100 ms with return value 0
+
+## z:\Chao\src\2015_sort_3num\test\in3.txt 
+2020/06/13 周六 10:23:28.60 
+0
+-----------------------------------------------
+Process exited after 100 ms with return value 0
+