In the sample() function I have code below

```
while (idx != newline_character and counter != 50):
# Step 2: Forward propagate x using the equations (1), (2) and (3)
a = np.tanh(np.dot(Wax, x) + np.dot(Waa, a_prev) + b)
z = np.dot(Wya, a) + by
y = softmax(z)
# For grading purposes
np.random.seed(counter + seed)
# Step 3: Sample the index of a character within the vocabulary from the probability distribution y
# (see additional hints above)
idx = np.random.choice(list(range(len(vocab_size)), p =y.ravel())
# Append the index to "indices"
indices.append(idx)
# Step 4: Overwrite the input x with one that corresponds to the sampled index `idx`.
# (see additional hints above)
x =np.zeros(shape = (vocab_size,1))
x[idx] = 1
# Update "a_prev" to be "a"
a_prev = a
# for grading purposes
seed += 1
counter +=1```
and get the error like here
File "<ipython-input-25-8fbe214c5ea4>", line 61
indices.append(idx)
^
SyntaxError: invalid syntax
can someone help?
```