What's wrong with my code?

Question

I try to solve average world lenght problem.
I got 4/5. I just wrong at test 1. I count it manually and get 3,..... If it rounded up, its must be 4.
Why the true output is 3?
This is my code
x = input()
y = x.split(" ")
n = int(len(y))
sum = 0
for i in y:
a = len(i)
sum = sum + int(a)
print((sum//n)+1)

Answer 1

A word may contain a punctuation, it doesn't count into the length of that word. For instance, the word 'abc.;,' has a length of 3 not 6.

Answer 2

Thanks a lot, i will try again