New to Java

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.util.Scanner;

public class MyFiles
{
private static BufferedReader in;

`public` `static` `void` `main (String[ ] args) throws` `IOException`  
`{`   
    `double` `max=0, min=10000000;`  

    `Product p_min=new` `Product("",0.0,0);`  
    `Product p_max=new` `Product("",0.0,0);`  
    `File j = new` `File("in.txt");`  

    `Scanner input = new` `Scanner(j);`  
    `PrintWriter pw = new` `PrintWriter(new` `File("out.txt"));`  
    `String line;`            
    `in = null;`  
    `while((line=in.readLine())!=null)`  
    `{`  

        `String[] array=line.split(";");`  
        `String name=array[0];`  
        `double` `price=Double.valueOf(array[1]);`  
        `int` `quantity=Integer.valueOf(array[2]);`  
        `if(price>max)`  
        `{`  
            `max=price;`  
            `p_max=new` `Product(name,price,quantity);`  
        `}`  
        `if(price<min)`  
        `{`  
            `min=price;`  
            `p_min=new` `Product(name,price,quantity);`  
        `}`  
    `}`  
   `pw.println("Product with maximum price is:"+p_max);`  
    `System.out.println("Product with maximum price is:"+p_max);`  
  `System.out.println("Product with minimum price is:"+p_min);`  
    `pw.println("Product with minimum price is:"+p_min);`  
    `input.close();`  
    `pw.close();`  
  `}`  

}

public class Product extends MyFiles {

    `private` `String name;`  
    `private` `double` `price;`  
    `private` `int` `quantity;`      
    `public` `Product(String name, double` `price, int` `quantity)`  
    `{`  
        `this.name=name;`  
        `this.price=price;`  
        `this.quantity=quantity;`  
    `}`  
    `public` `Product(Product p)`  
    `{`  
        `p.name=name;`  
      
 `p.price=price;`  
        `p.quantity=quantity;`  
    `}`  
    `public` `String toString()`  
    `{`  
        `return` `name+" which has the price "+price+" and is present in a quantity of "+quantity;`  
    `}`  
`}`  

Input file :
sugar;1.5;10

milk;4.5;100

grain;3.2;200

I got these errors :

Exception in thread "main" java.io.FileNotFoundException: in.txt (The system cannot find the file specified)
at java.base/java.io.FileInputStream.open0(Native Method)
at java.base/java.io.FileInputStream.open(FileInputStream.java:211)
at java.base/java.io.FileInputStream.<init>(FileInputStream.java:153)
at java.base/java.util.Scanner.<init>(Scanner.java:639)
at MyFiles.main(MyFiles.java:29)