```java public class ComplexNumber { private double real; private double imaginary; public ComplexNumber(double real, double imaginary) { this.real = real; this.imaginary = imaginary; } public double getReal() { return real; } public void setReal(double real) { this.real = real; } public double getImaginary() { return imaginary; } public void setImaginary(double imaginary) { this.imaginary = imaginary; } @Override public String toString() { return "ComplexNumber{" + "real=" + real + ", imaginary=" + imaginary + '}'; } public static void main(String[] args) { ComplexNumber c1 = new ComplexNumber(3, 4); ComplexNumber c2 = new ComplexNumber(1, -2); System.out.println("c1: " + c1); System.out.println("c2: " + c2); } } ```