HELP this code run on DR.JAVA app but not on sololearn playground.

Question

import java.util.Scanner;
class CALCULATOR{
public static void main(String[]made_by_Himanshu){
System.out.println("Enter The First Number = ");
Scanner scan1 = new Scanner(System.in);
double number_1=scan1.nextDouble();
System.out.println("Enter The Second Number = ");
Scanner scan2 = new Scanner(System.in);
double number_2=scan2.nextDouble();
System.out.println("Enter O for ADDITION, 1 for SUBSTRACTION, 2 for MULTIPLICATION and 3 for DIVISION");
Scanner scan=new Scanner(System.in);
int operate=scan.nextInt();
if(operate<1){
System.out.println(number_1+number_2);
}else if(operate>0&&operate<2){
System.out.println(number_1-number_2);
}else if(operate>1&&operate<3){
System.out.println(number_1*number_2);
}else if(operate>2&&operate<4){
System.out.println(number_1/number_2);
}
}
}