Why doesn't the split function return all values ​​in a list?

Question

Python

I have a file with two lines. The first contains one number, and the second contains 5 numbers separated by a space. Here is the code:

file = open('standard input.txt', 'r')
n = int(file.readline())
t = str(file.readline())
t1 = t.split(' ')

And here is the txt file:
5
30 45 30 35 30
When I run the program, only numbers 45 and 35 appear in the list t1. How to solve this problem?