Error: The method nextInt() is undefined for the type java.io.Reader?

Question

Java

I'm new to
writing a program.
Finished, I click compilation and then Error: The method nextInt() is undefined for the type java.io.Reader
here is the program.
help me please

import java.lang.*;
import java.io.Reader;
import java.util.Scanner;
public class karlic20
{
  Scanner sc = new Scanner(System.in);
  public static void main(String[]args)
  {
    System.out.println("Введите данные уравнения");
    System.out.println("ax^2+bx+c");
    {
    System.out.println("Введите a");
    int a=Reader.nextInt();
    System.out.println("Введите b");
    int b=Reader.nextInt();
    System.out.println("Введите c");
    int c=Reader.nextInt();
    {
      System.out.println("Вы ввели"+ a +"x^2+"+ b +"x+"+c);
    int d,b1;
    double d1,x1,x2,x11,x22;
    b1=b*b;
      d=b1-4*a*c;
      d1=Math.sqrt(d);
        x11=-b+d1;
      x1=x11/2*a;
        x22=-b-d1;
        x2=x22/2*a;
     System.out.println("x1 равен:"+x1+"x2 равен:"+x2);
       }
    }
}
}

Answer 1

That's what Sergei meant.
You should have moved the Scanner inside the main method. + Instead, Reader use sc

import java.lang.*;
import java.io.Reader;
import java.util.Scanner;
public class karlic20 {
    
    public static void main(String[]args)
    {
      Scanner sc = new Scanner(System.in);
      System.out.println("Введите данные уравнения");
      System.out.println("ax^2+bx+c");
      {
      System.out.println("Введите a");
      int a=sc.nextInt();
      System.out.println("Введите b");
      int b=sc.nextInt();
      System.out.println("Введите c");
      int c=sc.nextInt();
      {
        System.out.println("Вы ввели"+ a +"x^2+"+ b +"x+"+c);
      int d,b1;
      double d1,x1,x2,x11,x22;
      b1=b*b;
        d=b1-4*a*c;
        d1=Math.sqrt(d);
          x11=-b+d1;
        x1=x11/2*a;
          x22=-b-d1;
          x2=x22/2*a;
       System.out.println("x1 равен:"+x1+"x2 равен:"+x2);
         }
      }
  }
}