public class Kal0{
public static void main(String[] args){
int x=0;
String number="";
String sign="";
java.util.Vector plus=new java.util.Vector();
java.util.Vector minus=new java.util.Vector();
while
{
System.out.println("Enter a number");
java.util.Scanner scan = new java.util.Scanner(System.in);
number = String.valueOf(scan.next());
System.out.println("Enter a math operation");
java.util.Scanner scan2 = new java.util.Scanner(System.in);
sign = String.valueOf(scan2.next());
}
double [] a=new double[n];
String b[]=new String[n];
for(int i=0; i<a.length; i++){
if(b[i].equals("+"){x+=a[i];}
if(b[i].equals("-"){x-=a[i];}
}