    import scala.io._
    object Main {
    	def main(args: Array[String]) {
    		val input = Source.fromInputStream(System.in)
    		val lines = input.getLines.toSeq
     
    		var size = lines(0).split(" ").map(_.toInt)
    		var res: Long = 0
    			
    		if(size(0) > 2 && size(1) > 2) {
    			res = (size(0) - 2) * (size(1) - 2)
    		}else if(size(0) == 1 || size(1) == 1) {
    			res = (size(0) * size(1)) - 2
    		}else{
    			res = 0
    		}
    		println(res)
    	}
    }