Public static void main(string[] args) { scanner scnr = new scanner(system. in); double wallheight = 0.0; double wallwidth = 0.0; double wallarea = 0.0; double gallonspaintneeded = 0.0; final double squarefeetpergallons = 350.0; // implement a do-while loop to ensure input is valid // prompt user to input wall's height system. out. println("enter wall height (feet): "); wallheight = scnr. nextdouble(); // implement a do-while loop to ensure input is valid // prompt user to input wall's width system. out. println("enter wall width (feet): "); wallwidth = scnr. nextdouble(); // calculate and output wall area