Fraction implementation using oops in java, Java

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/*package whatever //do not write package name here */

import java.io.*;
import java.util.*;
import java.lang.*;
class Fraction{
    private int numerator;
    private int denominator;
    public Fraction(int numerator,int denominator)
    {
        this.numerator=numerator;
        this.denominator=denominator;
        simplify();
        
    }
    public int getDenominator()
    {
        return denominator;
    }
    public int getNumerator()
    {
        return numerator;
    }
    public void setNumerator(int n)
    {
        this.numerator=n;
        simplify();
    }
     public void setDenominator(int d)
    {
        this.denominator=d;
        this.simplify();
    }
    public void print()
    {
        if(denominator==1)
        {
           System.out.println(numerator);
        }
        else
        System.out.println(numerator+" / "+denominator);
    }
    private void simplify()
    {
        int gcd=1;
        for(int i=2;i<=Math.min(numerator,denominator);i++)
        {
            if(numerator%i==0 && denominator%i==0)
            {
                gcd=i;
            }
        }
        numerator=numerator/gcd;
        denominator=denominator/gcd;
    }
    public static Fraction add(Fraction f1,Fraction f2)
    {
        
        int x=f1.numerator*f2.denominator+f2.numerator*f1.denominator;
        int y=f1.denominator*f2.denominator;
        Fraction f3=new Fraction(x,y);
        return f3;
        
    }
    public void add(Fraction f)
    {
        this.numerator=this.numerator*f.denominator+this.denominator*f.numerator;
        this.denominator=this.denominator*f.denominator;
        simplify();
    }
    public void multiply(Fraction f)
    {
        this.numerator=this.numerator*f.numerator;
        this.denominator=this.denominator*f.denominator;
        simplify();
    }
}
class Rextester {
	public static void main (String[] args) {
	    Fraction f1=new Fraction(20,30);
	    f1.print();
	    f1.setNumerator(12); 
        f1.print();
        f1.setNumerator(10);
        f1.setDenominator(30);
        f1.print();
        Fraction f2=new Fraction(30,40);
        f2.print();
        f1.add(f2);
        f1.print();
      Fraction f3=new Fraction(4,5);
        f3.multiply(f2);
        f3.print();
        Fraction f4=Fraction.add(f3,f2);//3/5 3/4
        f4.print();

}
}

[ + ] Show input
Compilation time: 0.72 sec, absolute running time: 0.22 sec, cpu time: 0.18 sec, memory peak: 38 Mb, absolute service time: 0,97 sec