Best WAP to find whether a given number is prime or not.

package com.kapish;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        //Prime Number
        Scanner sc= new Scanner(System.in); //System.in --> input from keyboard
        System.out.print("Enter a Integer: ");
        int a = sc.nextInt();//reads number

        //For Making it Efficient
        int b = (a/2)+1;
        int notp = 1;
        int f =0;

        //for loop to find who is dividing it
        for(int i = 2; i <= b; i++)
        {
            // condition for non Prime number
            if(a % i == 0) {
                f=i;
                notp=1;
                break;
            }
            else{
                notp=0;
            }

        }
        if (notp==0){
            System.out.println(a+"ya Boy! It's Prime number : ");
        }
        else{
            System.out.println("Not A Prime number since its divisble by "+f);
        }



    }
}