public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    System.out.println("enter n1:");
    int n1=sc.nextInt();
    System.out.println("enter n2:");
    int n2=sc.nextInt();
    int i;
    int j;
    int flag=0;
    for(i=n1;i<=n2;i++)
    {
    for(j=2;j<i ;j++)
    {
        if(i % j==0)
        {
            flag++;
            break;
        }
    }
    if(flag==0)
        {
         System.out.println("i= "+i);
        }
    flag=0;

    }
}