diff --git a/1-1.cpp b/1-1.cpp
new file mode 100644
index 0000000..008d2ac
--- /dev/null
+++ b/1-1.cpp
@@ -0,0 +1,90 @@
+#include <iostream>
+#include <vector>
+#include <string>
+#include <sstream>
+using namespace std;
+
+class directory{
+    vector<string> files;
+    int N;
+    public:
+    directory() {}
+    ~directory() {}
+    void add_file(string f) {
+        files.push_back(f);
+    }
+    void copy_file(string name,int n=1) {
+        // check exist
+        bool flag = false;
+        for(string j : files) {
+            if (name == j) flag = true;
+        }
+        if (!flag) {
+            cout<<"error"<<endl;
+            return;
+        }
+
+        string back = name;
+        int index = name.rfind('.',name.size());
+        if(index == -1) {
+            for(int i = 1;i <= n;i++){
+                back = name;
+                back.append('_' + to_string(i));
+                bool flag = false;
+                for(string j : files) {
+                    if (back == j) flag = true;
+                }
+                if (flag) {
+                    n++;
+                    continue;
+                }
+                cout<<back<<' ';
+                add_file(back);
+            }
+        } else {
+            for(int i = 1;i <= n;i++){
+                back = name;
+                back.replace(index,1,'_' + to_string(i) + '.');
+                bool flag = false;
+                for(string j : files) {
+                    if (back == j) flag = true;
+                }
+                if (flag) {
+                    n++;
+                    continue;
+                }
+                cout<<back<<' ';
+                add_file(back);
+            }
+        }
+
+    }
+};
+
+int main() {
+    directory dir;
+    for(int i=0;i<2;i++){
+        string temp,cmd;
+        vector<string> part;
+        getline(cin,cmd);
+        stringstream ss(cmd);
+        while (ss>>temp) {
+            part.push_back(temp);
+        }
+        if (part[0] == "copy" && part.size() == 3) {
+            dir.copy_file(part[1],stoi(part[2]));
+            cout<<endl;
+        }
+        else if(part[0] == "copy") {
+            dir.copy_file(part[1],1);
+            cout<<endl;
+        }
+        else {
+            for(string j: part) {
+                dir.add_file(j);
+            }
+        }
+    }
+    system("pause");
+    return 0;
+}
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