Why occur ValueError in my simple code in Python? [duplicate]

enter image description here

here is my code

a = int(input())
b = int(input())

print(a, b)

and run result is here.

C:\PycharmProjects\venv\Scripts\python.exe C:/PycharmProjects/main.py
1
10
Traceback (most recent call last):
  File "C:\PycharmProjects\main.py", line 2, in <module>
    b = int(input())
ValueError: invalid literal for int() with base 10: ''

Process finished with exit code 1

i just input 5(enter)10 but error has occurred

in debug mode, it is OK Why occur ValueError in code?? please refer to attached picture also. thanks..!!