diff --git a/201816040206/Ex03_13/Ex03_13.cpp b/201816040206/Ex03_13/Ex03_13.cpp
new file mode 100644
index 0000000..e3aa904
--- /dev/null
+++ b/201816040206/Ex03_13/Ex03_13.cpp
@@ -0,0 +1,26 @@
+#include <iostream>
+#include "Invoice.h"
+using namespace std;
+
+int main()
+{
+    string Number;
+    string Describe;
+    int    Sale;
+    int    Price;
+
+    cout <<"Number:"<<endl;
+    cin  >>Number;
+    cout <<"Describe"<<endl;
+    cin  >>Describe;
+    cout <<"Salenumber"<<endl;
+    cin  >>Sale;
+    cout <<"Price"<<endl;
+    cin  >>Price;
+
+    Invoice invoice( Number, Describe, Sale, Price);
+    cout <<"output"endl;
+    cout <<invoice.getInvoiceAmount();
+    return 0;
+
+}
diff --git a/201816040206/Ex03_13/Invoice.cpp b/201816040206/Ex03_13/Invoice.cpp
new file mode 100644
index 0000000..bc606a4
--- /dev/null
+++ b/201816040206/Ex03_13/Invoice.cpp
@@ -0,0 +1,58 @@
+//INcoice .cpp
+
+#include <iostream>
+#include "Invoice.h"
+using namespace std;
+
+Invoice::Invoice(string number,string describe,int sale,int price)
+{
+    setInvoiceNumber(number);
+    setInvoiceDescribe(describe);
+    setInvoiceSalenumber(sale);
+    setInvoiceSaleprice(price);
+}
+
+void Invoice::setInvoiceNumber(string Number)
+{
+    number=Number;
+}
+string Invoice::getInvoiceNumber()
+{
+    return number;
+}
+
+void Invoice::setInvoiceDescribe(string Describe)
+{
+    describe=Describe;
+}
+string Invoice::getInvoiceDescribe()
+{
+    return describe;
+}
+void Invoice::setInvoiceSalenumber(int Sale)
+{
+    if(Sale<=0)
+      sale=0;
+    else
+        sale=Sale;
+}
+int Invoice::getInvoiceSalenumber()
+{
+    return sale;
+}
+void Invoice::setInvoiceSaleprice(int Price)
+{
+    if(Price<=0)
+        price=0;
+    else
+        price=Price;
+}
+int Invoice::getInvoiceSaleprice()
+{
+    return price;
+}
+
+int Invoice::getInvoiceAmount()
+{
+    return sale*price;
+}
diff --git a/201816040206/Ex03_13/Invoice.h b/201816040206/Ex03_13/Invoice.h
new file mode 100644
index 0000000..c40484f
--- /dev/null
+++ b/201816040206/Ex03_13/Invoice.h
@@ -0,0 +1,27 @@
+//Github  3.13
+
+#include <iostream>
+#include <string.h>
+
+using namespace std;
+
+class Invoice
+{
+public:
+    Invoice (string,string,int ,int );
+
+    void    setInvoiceNumber(string);
+    string  getInvoiceNumber();
+    void    setInvoiceDescribe(string);
+    string  getInvoiceDescribe();
+    void    setInvoiceSalenumber (int );
+    int     getInvoiceSalenumber();
+    void    setInvoiceSaleprice(int );
+    int     getInvoiceSaleprice();
+    int     getInvoiceAmount();
+private:
+    string number;
+    string describe;
+    int    sale;
+    int     price;
+};