One way to estimate the height of a child is to use one of the following
formulas, which use the height of the parents:

For the male child:
	H = (M*13/12 + F)/2

For the female child:
	H = (M + F*12/13)/2

where M is the height of the mother and F is the height of the father.
Write a program that takes the gender of the child, the height of the
mother and the father (respectively) in feet and inches, and outputs
the height of the child in feet and inches. The program program should
repeat until it is given a nonsense gender for the child. Use ints to
store the heights.