import numpy as np
import matplotlib.pyplot as plt

def f(x, y):
    return (x**2 + y**2 - 1)**3 - x**2 * y**3
x = np.linspace(-1.5, 1.5, 400)
y = np.linspace(-1.5, 1.5, 400)
X, Y = np.meshgrid(x, y)
Z = f(X, Y)

# Plot the curve
plt.contour(X, Y, Z, levels=[0], colors='red')
plt.xlabel('x')
plt.ylabel('y')
plt.gca().set_aspect('equal', adjustable='box')
plt.grid(True)
plt.show()