diff --git a/README.md b/README.md
index 74267d7..9f01b47 100644
--- a/README.md
+++ b/README.md
@@ -108,6 +108,9 @@ ll ksm(ll a,ll b,ll M){
 
 ## Day9
 ### 字典树与异或极值
+### [U88589](./day10/U88589/U88589.pdf)
+> 值域线段树，线段树维护一个桶
+
 
 ## Day11
 [树状数组MD](./day11/FenwickTree/FenwickTree.md)
diff --git a/day10/U88589/U88589.cpp b/day10/U88589/U88589.cpp
index f92893a..dd48467 100644
--- a/day10/U88589/U88589.cpp
+++ b/day10/U88589/U88589.cpp
@@ -8,7 +8,6 @@ int a[MAX_N];
 int readint();
 
 int main(){
-    // auto a  = new int[MAX_N];
     const int n = readint();
     for(int i=1;i<=n;i++){
         const int m = readint();
diff --git a/day10/U88589/U88589.pdf b/day10/U88589/U88589.pdf
new file mode 100644
index 0000000..d7d9fd1
Binary files /dev/null and b/day10/U88589/U88589.pdf differ