public class Fraction {
	private int numerator = 0;
	private int denominator = 1;

	public Fraction(int whole, int numer, int denom) { //3 params
		if (denom==0) {
			throw new IllegalArgumentException("Your denominator can't be zero!");
		}
		else if (denom<0) {
			numer*=-1;
			denom*=-1;
		}

		if (numer<0) {
			throw new IllegalArgumentException("Your numerator can't be negative!");
		}

		int numerator = whole * denom + numer;
		int denominator = denom;

		int gcd = gcd(numerator, denominator);

		numerator /= gcd;
		denominator /=gcd;
	}
	public Fraction(int numer, int denom) { //2 params
		if (denom==0) {
			throw new IllegalArgumentException("You can't divide by zero!");
		}
		else if (denom<0) {
			numer*=-1;
			denom*=-1;
		}

		numerator = numer;
		denominator = denom;

		int gcd = gcd(numerator, denominator);

		numerator /= gcd;
		denominator /=gcd;
	}
	public Fraction(int whole) { //1 param, whole number
		numerator = whole;
		denominator = 1;
	}
	public Fraction(String st) { //why did you type a string ):   WORK ON THISSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS
		String s=st;
		int under = getIndex(s,'_');
		int div = getIndex(s,'/');

		int numer=0;
		int denom=0;

		if (under==-1 && div==-1) {
			numer=Integer.parseInt(s);
			denom=1;
		}
		else if(under==-1) {
			numer=Integer.parseInt(s.substring(under+1,div));
			denom=Integer.parseInt(s.substring(div+1,s.length()));
		}
		else {
			denom=Integer.parseInt(s.substring(div+1,s.length()));
			if (s.charAt(0)!='-') {
				numer=Integer.parseInt(s.substring(0,under)) * denom + Integer.parseInt(s.substring(under+1,div));
			}
			else {
				numer=Integer.parseInt(s.substring(0,under)) * denom - Integer.parseInt(s.substring(under+1,div));
			}
		}

		if (denom < 0) {
			throw new IllegalArgumentException("Your denominator can't be less than zero!");
		}
		else if (denom == 0) {
			throw new IllegalArgumentException("You can't divide by zero!");
		}

		this.numerator=numer;
		this.denominator=denom;

	}
	public Fraction add(Fraction f) { //addition
		int gcd=gcd(f.getNumerator(), f.getDenominator());
		int lcm=(this.denominator*f.getDenominator())/gcd;

		int factor1 = lcm/this.denominator;
		int factor2 = lcm/f.getDenominator();

		int numerator = this.numerator * factor1 + f.getNumerator() * factor2;
		int denominator = lcm;

		gcd(numerator, denominator);

		numerator /= gcd;
		denominator /=gcd;

		return new Fraction(numerator,denominator);
	}
	public Fraction subtract(Fraction f) { //minus
		int gcd=gcd(f.getNumerator(), f.getDenominator());
		int lcm=(this.denominator*f.getDenominator())/gcd;

		int factor1 = lcm/this.denominator;
		int factor2 = lcm/f.getDenominator();

		int numerator = this.numerator * factor1 - f.getNumerator() * factor2;
		int denominator=lcm;

		gcd(numerator, denominator);

		numerator /= gcd;
		denominator /=gcd;

		if (denominator<0) {
			numerator*=-1;
			denominator*=1;
		}

		return new Fraction(numerator,denominator);
	}
	public Fraction multiply(Fraction f) {
		int numerator = this.numerator * f.getNumerator();
		int denominator = this.denominator * f.getDenominator();

		int gcd = gcd(numerator,denominator);

		numerator /= gcd;
		denominator /=gcd;

		return new Fraction(numerator,denominator);
}
	public Fraction divide(Fraction f) {

		if (this.denominator == 0 || f.getDenominator() == 0) {
			throw new IllegalArgumentException("You can't divide by zero!");
		}
		int numerator = this.numerator * f.getDenominator();
		int denominator = this.denominator * f.getNumerator();

		int gcd = gcd(numerator,denominator);

		numerator /= gcd;
		denominator /=gcd;

		return new Fraction(numerator,denominator);
}
	public int getNumerator() {
		return numerator;
	}
	public int getDenominator() {
		return denominator;
	}
	public static int gcd(int a, int b) {
		a = Math.abs(a);
		b = Math.abs(b);

		while (b!=0) {
			int temp=b;
			b=a%b;
			a=temp;
		}
		return Math.abs(a);
	}
	public static int getIndex(String a, char c) {
		for (int i=0;i<a.length();i++) {
			if (a.charAt(i)==c) {
				return i;
			}
		}
		return -1;
	}
	public String toString() {
		if (this.denominator == 1) {
			return Integer.toString(this.numerator);
		}
		else if (Math.abs(this.numerator) < this.denominator) {
			return this.numerator + "/" + this.denominator;
		}
		else {
			return this.numerator / this.denominator + "_" + Math.abs(this.numerator % this.denominator) + "/" + this.denominator;
		}
	}
}