diff --git a/.gitignore b/.gitignore
index 9c0d336..b65d4ef 100644
--- a/.gitignore
+++ b/.gitignore
@@ -49,3 +49,4 @@ day4/U76034/chat
 day4/U287193/chat
 day4/U461920/fixed
 day5/hard/hard
+day5/perfect/perfect
diff --git a/README.md b/README.md
index 71bb89b..9333274 100644
--- a/README.md
+++ b/README.md
@@ -42,6 +42,10 @@ int main(){
 #### 通过异色中转
 #### 环
 
+## Day5
+### 需要学习的点
+>区间最值
+
 # 排序
 ## 稳定性
 >隔着老远swap一般不稳定
diff --git a/day5/perfect/perfect.cpp b/day5/perfect/perfect.cpp
new file mode 100644
index 0000000..5e887f0
--- /dev/null
+++ b/day5/perfect/perfect.cpp
@@ -0,0 +1,30 @@
+//暴力10/100points
+
+#include<bits/stdc++.h>
+using namespace std;
+
+const int MAX_N=3e5+5;
+int n;
+int a[MAX_N];
+int ans=INT_MIN;
+
+int main(){
+    cin.sync_with_stdio(false);
+    cin.tie(0);
+    cin>>n;
+    for(int i=1;i<=n;i++){
+        cin>>a[i];
+    }
+    for(int l=1;l<=n;l++){
+        for(int r=l;r<=n;r++){
+            int max_num=INT_MIN;
+            int min_num=INT_MAX;
+            for(int i=l;i<=r;i++){
+                max_num=max(max_num,a[i]);
+                min_num=min(min_num,a[i]);
+            }
+            ans=max(ans,max_num^min_num);
+        }
+    }
+    cout<<ans<<endl;
+}
\ No newline at end of file