C++ code please

Write a C++ program that uses nested for-loops to display a rectangle of symbols (see example). The program should ask the user to enter an integer n representing the number of columns in the rectangle. The number n should be even and larger than 5. If the user input n is invalid, an appropriate message is displayed then exit the program. The program should display a rectangle with the left half filled with the character '+' and the right half is filled with the character '='. Note the number of rows equals half the number of columns