//Compute.java

package store;

import java.io.IOException;

public class Compute {
   public static int add(int numA,int numB) {
       return numA+numB;
   }
   public static double squareRoot(int num) throws Exception {
       if(num<0)
           throw new Exception("InvalidInputException");
       double temp,sqrt;
       sqrt=num/2;
       temp=0;
       while(sqrt!=temp) {
           temp=sqrt;
           sqrt = (num/temp + temp)/2;
       }
       return sqrt;
   }
   public static void main(String[] args) throws NumberFormatException, Exception {
       if(args.length==0)
           throw new IOException();
       try {
           for(int **0;i<args.length;i++)
           Integer.parseInt(args[i]);
       }catch(Exception e) {
           throw new IOException();
       }
       if(args.length==2)
           System.out.println(add(Integer.parseInt(args[0]),Integer.parseInt(args[1])));
       else if(args.length==1)
           System.out.println(squareRoot(Integer.parseInt(args[0])));
          
   }
}

Note:- Tested this code on online java compiler whose output is as follows