diff --git a/q1.cpp b/q1.cpp
new file mode 100644
index 0000000..90ecae7
--- /dev/null
+++ b/q1.cpp
@@ -0,0 +1,170 @@
+#include <iostream>
+ #include <string>
+ using namespace std;
+ const int MAX = 100;
+ 
+ template<typename T,typename F>
+ int myfind(T* begin, T* end, F f) {
+    for (T* itr = begin; itr != end; itr++) {
+        if (f(*itr)) {
+            return itr - begin;
+        }
+    }
+    return -1;
+}
+ 
+ class AbstractUser {
+ public:
+     AbstractUser(const string& username, const string& password)
+         : username(username), password(password) {}
+ 
+     virtual ~AbstractUser() = default;
+ 
+     virtual void displayRole() const = 0;
+     virtual bool hasAccessToSee(AbstractUser*) const = 0;
+ 
+     string getUsername() const {
+         return username;
+     }
+     bool isPasswordCorrect(const string& pass) {
+         return (pass == password);
+     }
+ 
+ protected:
+     string username;
+     string password;
+ };
+ 
+ class Student : public AbstractUser {
+ public:
+     Student(const string& username, const string& password, int grade)
+         : AbstractUser(username, password), grade(grade) {}
+ 
+     void displayRole() const override {
+         cout << "Student: " << username << ", Grade: " << grade << endl;
+     }
+     bool hasAccessToSee(AbstractUser* user) const override {
+         return false;
+     }
+ 
+ private:
+     int grade;
+ };
+ 
+ class Staff : public AbstractUser {
+ public:
+     Staff(const string& username, const string& password, int salary)
+         : AbstractUser(username, password), salary(salary) {}
+ 
+     void displayRole() const override {
+         cout << "Staff: " << username << ", Salary: " << salary << endl;
+     }
+     bool hasAccessToSee(AbstractUser* user) const override {
+         if (dynamic_cast<Student*>(user) != nullptr) {
+             return true;
+         }
+     }
+ 
+ private:
+     int salary;
+ };
+ 
+ class Admin : public Staff {
+ public:
+     Admin(const string& username, const string& password, int salary)
+         : Staff(username, password, salary) {}
+ 
+     void displayRole() const override {
+ 
+         cout << "Admin ";
+         Staff::displayRole();
+     }
+
+     bool hasAccessToSee(AbstractUser* user) const override {
+        if (dynamic_cast<Student*>(user) != nullptr) {
+            return true;
+        }
+
+        if(dynamic_cast<Staff*>(user) != nullptr) {
+            return true;
+        }
+    }
+     
+ };
+ 
+ AbstractUser* current_user;
+ AbstractUser* users[100];
+ int user_cnt;
+
+ void print() {
+     if (!current_user) {
+         return;
+     }
+     for (AbstractUser* user : users) {
+         if (current_user->hasAccessToSee(user)) {
+             user->displayRole();
+         }
+     }
+ }
+ 
+ void addStudent(string username, string password, int grade) {
+    int index = myfind(users, users + user_cnt, [&](AbstractUser* u) {
+        return u->getUsername() == username;});
+
+     if (index != -1) {
+         return;
+     }
+     if (dynamic_cast<Admin*>(current_user) == nullptr){
+         cout << "permision denied"<<endl;
+         return;
+     }
+     Student* st = new Student(username, password, grade);
+     users[user_cnt ++] = st;
+ }
+ 
+ int main() {
+     Student s("erfan", "pass1", 12);
+     Student s2("rasool", "pass2", 12);
+     Staff st1("alireza", "staffpass", 1000);
+     Staff st2("kiyan", "staffpass", 1000);
+     Admin a("yalda", "adminpass",1200);
+     user_cnt = 5;
+    users[0] = &s;
+    users[1] = &s2;
+    users[2] = &st1;
+    users[3] = &st2;
+    users[4] = &a;
+ 
+     while (1) {
+         string username, password;
+         cout << "username: ";
+         cin >> username;
+         cout << "password:";
+         cin >> password;
+         int index = myfind(users, users + user_cnt, [&](AbstractUser* u) {return u->getUsername() == username && u->isPasswordCorrect(password);});
+         if (index!=-1) {
+             current_user = users[index];
+             break;
+         }
+ 
+     }
+     int choice;
+     while (1) {
+         cout << "1.print" << endl;
+         cout<<"2.add student"<<endl;
+         cin >> choice;
+         if (choice == 1) {
+             print();
+         }
+         else {
+             string user, pass;
+             int grade;
+             cin >> user >> pass >> grade;
+             addStudent(user, pass, grade);
+ 
+         }
+ 
+     }
+ 
+     return 0;
+ }
\ No newline at end of file