$.$ Write blocks of code to perform the functions used in the following main program. Your blocks must match the given title lines. Each block should be a short function of only a few lines. int main$()\{//($a$)$ Print the number of odd arguments, here $1$ cout $<<$ numberOdd$(7,8)<<$ endl; $//($b$)$ Print closest integer here $4$ cout $<<$ closest$(3\mathrm{.}75)<<$ endl; $//($c$)$ Print maximum value, here $4$ cout $<<$ max$(3,1,4,1)<<$ endl; $//($d$)$ Print the first digit, assume argument is positive. Here $1.$ cout $<<$ firstDigit$(19683)<<$ endl; return $0$; $\}$ a$.$ int numberOdd$($int x$,$ int y$)$ b$.$ int closest$($double x$)$ c$.$ int max$($int a$,$ int b$,$ int c$,$ int d$)$ d$.$ int firstDigit$($int x$)$