Write a program to determine the coefficients of expanded form of (aX+bY+c)n.

Every line in bold is questions to ask whoever runs the program to enter values or commands (y or n) at the console.

A sample session: 

What are the coefficients of X and Y? // values of a & b 
2 -1 //provided at run-time 

What are the values of constant c and n? 
5 4 //provided at run-time 

The coefficients are: 
answer after program calculates //console output 
Continue? 

Y //provided at run-time 

What are the coefficients of X and Y? 

3 -4 //provided at run-time 

What are the values of constant c and n? 
2 3 //provided at run-time 

The coefficients are: 

answer after program calculates //console output 

Continue? 

N ' // provided at run-time 

Goodbye! //final console output