diff --git a/HDOJ/3527.cpp b/HDOJ/3527.cpp
new file mode 100644
index 0000000..5f99c5e
--- /dev/null
+++ b/HDOJ/3527.cpp
@@ -0,0 +1,46 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(0);
+    int a, b, c;
+    string name;
+    while (cin >> a >> b >> c)
+    {
+        set<string> s;
+        vector<string> v;
+        for (int i=0; i<a; i++)
+        {
+            cin >> name;
+            s.insert(name);
+        }
+        for (int j=0; j<b; j++)
+        {
+            cin >> name;
+            if (s.count(name)) v.push_back(name);
+        }
+        for (int k=0; k<c; k++)
+        {
+            cin >> name;
+            for (int i=0; i<v.size(); i++)
+            {
+                if (v[i] == name)
+                {
+                    v.erase(v.begin()+i);
+                }
+            }
+        }
+        if (v.empty()) cout << "No enemy spy\n";
+        else
+        {
+            int sz = v.size();
+            cout << v[0];
+            for (int i=1; i<sz; i++)
+                cout << " " << v[i];
+            cout << "\n";
+        }
+    }
+    return 0;
+}