Implement the following three functions used in the main function given below. c$.$ int numberEven$($int x$,$ int y$,$ int z$)$ returns how many of its three arguments are even. d$.$ int min$($int a$,$ int b$,$ int c$,$ int d$)$ returns the minimum of the four arguments. e$.$ int closest$($double x$)$ returns the closest integer to argument x$.$ f$.$ int evenLessOdd$($int n$)$ returns the sum of the even valued digits minus the sum of the odd valued digits of the positive integer parameter.