# W1 Assignment 1 Exercise 4: Wrong shape for caches

Hi, I am doing Assignment 1 for Week 1 of Sequence models(C5).

In Exercise 4, I keep getting error of:

AssertionError: Wrong shape for caches. 10 != 16

I don’t know what I did wrong. Can someone help me with this issue?

If you look at the core logic in that function, the `caches` variable will get an entry for every iteration of the “for” loop there. And the range on that loop is `T_x`. So it looks like you must be initializing that value incorrectly. There are several test cases in that test cell and I added a bunch of print statements to my code. Here’s what I see:

``````T_x 7
c.shape (5, 10, 7)
y.shape (2, 10, 7)
len(caches) 2
len(caches[0]) 7
a[4][3][6] =  0.17211776753291672
a.shape =  (5, 10, 7)
y[1][4][3] = 0.9508734618501101
y.shape =  (2, 10, 7)
caches[1][1][1] =
[ 0.82797464  0.23009474  0.76201118 -0.22232814 -0.20075807  0.18656139
0.41005165]
c[1][2][1] -0.8555449167181981
len(caches) =  2
T_x 16
c.shape (3, 13, 16)
y.shape (2, 13, 16)
len(caches) 2
len(caches[0]) 16
All tests passed
``````

So my guess is that for some reason you are getting `T_x` as 10 in that last test case. So how could that happen? Try printing your `T_x` values and see what you are getting.