def METHOD_NAME(x, y):
    a = np.exp(-( (x - 2)**2/0.7 + (y - 4)**2/1.2) + (x - 2)*(y - 4)/1.6 )
    b = np.exp(-( (x - 4)**2/3 + (y - 2)**2/2.) )
    c = np.exp(-( (x - 4)**2/0.5 + (y - 4)**2/0.5) + (x - 4)*(y - 4)/0.5 )
    d = np.sin(3.1415 * x)
    e = np.exp(-( (x - 5.5)**2/0.5 + (y - 5.5)**2/.5) )
    return 2*a + b - c + 0.17 * d + 2*e