public class HelloWorld{
    public static void main(String[] args) {
  int age1=24;
  int age2=18;
  int age3=36;
  int age4=27;
  int sum=ag1+age2+ag3+age4;
  double avg=sum/4;
  int minus=age1-age2;
  int newAge=--age1;
        System.out.println("年龄总和："+sum);
     System.out.println("平均年龄："+avg);
  System.out.println("年龄差值："+minus);
  System.out.println("自减后的年龄："+newAge);
  } 
}