diff --git a/Test.cpp b/Test.cpp
index 6646d08..e88d3c6 100644
--- a/Test.cpp
+++ b/Test.cpp
@@ -3,21 +3,24 @@
 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++) {
+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;
 
+    return -1;
 }
 
 class AbstractUser {
 public:
     AbstractUser(const string& username, const string& password)
-        : username(username), password(password) {}
+        : username(username), password(password) {
+    }
 
     virtual ~AbstractUser() = default;
 
@@ -39,7 +42,8 @@ class AbstractUser {
 class Student : public AbstractUser {
 public:
     Student(const string& username, const string& password, int grade)
-        : AbstractUser(username, password), grade(grade) {}
+        : AbstractUser(username, password), grade(grade) {
+    }
 
     void displayRole() const override {
         cout << "Student: " << username << ", Grade: " << grade << endl;
@@ -55,15 +59,19 @@ class Student : public AbstractUser {
 class Staff : public AbstractUser {
 public:
     Staff(const string& username, const string& password, int salary)
-        : AbstractUser(username, password), salary(salary) {}
+        : AbstractUser(username, password), salary(salary) {
+    }
 
     void displayRole() const override {
         cout << "Staff: " << username << ", Salary: " << salary << endl;
     }
     bool hasAccessToSee(AbstractUser* user) const override {
-        if (? != nullptr) {
+        if (user != nullptr && dynamic_cast<Student*>(user) != nullptr) {
             return true;
         }
+        else {
+            return false;
+        }
     }
 
 private:
@@ -73,14 +81,24 @@ class Staff : public AbstractUser {
 class Admin : public Staff {
 public:
     Admin(const string& username, const string& password, int salary)
-        : Staff(username, password, salary) {}
+        : Staff(username, password, salary) {
+    }
 
     void displayRole() const override {
 
         cout << "Admin ";
         Staff::displayRole();
     }
-    ?
+
+    bool hasAccessToSee(AbstractUser* user) const override {
+        if (user != nullptr && dynamic_cast<Admin*>(user) != nullptr) {
+            return true;
+        }
+        else {
+            return false;
+        }
+    }
+
 };
 
 AbstractUser* current_user;
@@ -92,46 +110,67 @@ void print() {
         return;
     }
     for (AbstractUser* user : users) {
-        if (?) {
+        if (user != nullptr) {
             user->displayRole();
         }
     }
 }
 
 void addStudent(string username, string password, int grade) {
-    int index = ?;
+
+    int index = -1;
+    for (int i = 0; users[i] != nullptr && i < 100; i++) {
+        index = i;
+        user_cnt = i;
+    }
+
     if (index != -1) {
         return;
     }
-    if (dynamic_cast<Admin*>(current_user) == nullptr){
-        cout << "permision denied"<<endl;
+
+    if (dynamic_cast<Admin*>(current_user) == nullptr) {
+        cout << "permision denied" << endl;
         return;
     }
     Student* st = new Student(username, password, grade);
-    users[user_cnt ++] = st;
+    users[user_cnt++] = st;
 }
 
 int main() {
+
     Student s("erfan", "pass1", 12);
     Student s2("rasool", "pass2", 12);
     Staff st("alireza", "staffpass", 1000);
-    Staff st("kiyan", "staffpass", 1000);
-    Admin a("yalda", "adminpass",1200);
+    Staff st2("kiyan", "staffpass", 1000);
+    Admin a("yalda", "adminpass", 1200);
+
     user_cnt = 5;
     users[0] = &s;
-    ?
-    ?
-    ?
-    ?
+    users[1] = &s2;
+    users[2] = &st;
+    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, ?);
-        if (index!=-1) {
+
+        auto is_existed = [username](AbstractUser* user) {
+
+            for (int i = 0; users[i] != nullptr && i < 100; i++) {
+                if (users[i]->getUsername() == username) {
+                    return true;
+                }
+            }
+            return false;
+            };
+
+        int index = myfind(users, users + user_cnt, is_existed);
+        if (index != -1) {
             current_user = users[index];
             break;
         }
@@ -140,7 +179,7 @@ int main() {
     int choice;
     while (1) {
         cout << "1.print" << endl;
-        cout<<"2.add student"<<endl;
+        cout << "2.add student" << endl;
         cin >> choice;
         if (choice == 1) {
             print();