public class Complex {
	public static final Complex ZERO = new Complex(0, 0);
	
	private final double a, b;
	public Complex(double a, double b) {
		this.a = a;
		this.b = b;
	}
	public Complex add(Complex o) {
		return new Complex(a + o.a, b + o.b);
	}
	public Complex sub(Complex o) {
		// TODO: Implement subtraction
		return ZERO;
	}
	public Complex mul(Complex o) {
		// TODO: Implement multiplication
		return ZERO;
	}
	public double getA() {
		return a;
	}
	public double getB() {
		return b;
	}
	public double magnitude() {
		// TODO: Implement magnitude calculation
		return 0;
	}
	public String toString() {
		return a + "+" + b + "i";
	}
}