Can someone help me I keep getting an error code on this line and I cannot figure it out.

```
cout <<"Encrypted digits:"; << digit_three; digit_four; digit_one; digit_two; << endl;// display encrypted numbers
```

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```
#include <iostream> // required to perform C++ stream I/O
#include <iomanip> // required to perform setprecision stream manipulator
using namespace std; // for accessing C++ Standard Library members
// function main begins program execution
int main()
{
int main=0;
int digit_one; // store digit one
int digit_two; // store digit two
int digit_three; // store digit three
int digit_four; // store digit four
cout <<"Enter four_digit number"; // asking the user to enter four_digit number
cin >>main; // four_digit number
digit_one=main%10; // digit_one is first four_digit number
digit_two=main/10%10; // digit_two is second four_digit number
digit_three=main/100%10; // digit_three is third four_digit number
digit_four=main/1000%10; // digit_four is fourth four_digit number
digit_one=(digit_one+7%10); // adds digit_one to 7 and mod 10
digit_two=(digit_two+7%10); // adds digit_two to 7 and mod 10
digit_three=(digit_three+7%10); // adds digit_three to 7 and mod 10
digit_four=(digit_four+7%10); // adds digit_four to 7 and mod 10
cout <<"Encrypted digits:"; << digit_three; digit_four; digit_one; digit_two; << endl;// display encrypted numbers
return 0; // indicate that program ended successfully
} // end function main
/**************************************************************************
* (C) Copyright 1992-2005 by Deitel & Associates, Inc. and *
* Pearson Education, Inc. All Rights Reserved. *
* DISCLAIMER: The authors and publisher of this book have used their *
* best efforts in preparing the book. These efforts include the *
* development, research, and testing of the theories and programs *
* to determine their effectiveness. The authors and publisher make *
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* and publisher shall not be liable in any event for incidental or *
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**************************************************************************/
```