diff --git a/POJ/2528_wuyiqi.cpp b/POJ/2528_wuyiqi.cpp
new file mode 100644
index 0000000..9b73491
--- /dev/null
+++ b/POJ/2528_wuyiqi.cpp
@@ -0,0 +1,72 @@
+#include<cstdio>
+#include<cstring>
+#include<algorithm>
+using namespace std;
+#define LL rt<<1
+#define RR rt<<1|1
+#define lson l,m,LL
+#define rson m+1,r,RR
+#define bug puts("bugbug");
+const int maxn = 11111;
+bool hash[10010];
+int col[maxn<<4];
+struct node{
+    int l,r;
+}q[10010];
+int ans;
+int x[maxn<<2];
+void pushdown(int rt){
+    if(col[rt]!=-1){
+        col[LL]=col[RR]=col[rt];
+        col[rt]=-1;
+    }
+}
+void update(int L,int R,int c,int l,int r,int rt){
+    if(L<=l&&r<=R){
+        col[rt]=c;
+        return ;
+    }
+    pushdown(rt);
+    int m=(l+r)>>1;
+    if(L<=m) update(L,R,c,lson);
+    if(R>m)  update(L,R,c,rson);
+}
+void query(int l,int r,int rt){
+    if(col[rt]!=-1){
+        if(!hash[col[rt]]) ans++;
+        hash[col[rt]]=true;
+        return;
+    }
+    if(l==r) return;
+    int m=(l+r)>>1;
+    query(lson);
+    query(rson);
+}
+int main(){
+    int n,i,j,t;
+    scanf("%d",&t);
+    while(t--){
+        int cnt=0;
+        scanf("%d",&n);
+        for(i=0;i<n;i++){
+            scanf("%d%d",&q[i].l,&q[i].r);
+            x[cnt++]=q[i].l;x[cnt++]=q[i].r;
+        }
+        sort(x,x+cnt);
+        int m=1;
+        for(i=1;i<cnt;i++)   if(x[i]!=x[i-1]) x[m++]=x[i];
+        for(i=m-1;i>=1;i--)  if(x[i]!=x[i-1]+1) x[m++]=x[i-1]+1;
+        sort(x,x+m);
+        memset(col,-1,sizeof(col));
+        for(i=0;i<n;i++){
+            int l=lower_bound(x,x+m,q[i].l)-x;
+            int r=lower_bound(x,x+m,q[i].r)-x;
+            update(l,r,i,0,m,1);
+        }
+        memset(hash,false,sizeof(hash));
+        ans=0;
+        query(0,m,1);
+        printf("%d\n",ans);
+    }
+    return 0;
+}