How to use subscript in wordclouds?

Question

Any idea how to use subscript in wordclouds? Thanks for your suggestions. This is what I tried so far:

import numpy as np
import matplotlib.pyplot as plt
from wordcloud import WordCloud

text = '$X_{i}$'
x, y = np.ogrid[:300, :300]

mask = (x - 150) ** 2 + (y - 150) ** 2 > 130 ** 2
mask = 255 * mask.astype(int)


wc = WordCloud(background_color="white", repeat=True, mask=mask)
wc.generate(text)
plt.figure(figsize=(10, 10))

plt.axis("off")
plt.imshow(wc, interpolation="bilinear")
plt.show()