# Lesson 2 Task 3: display all numbers from n to 1, then remove the first number and repeat while n > 0
# Author: Stanislav Mykhailenko
# License: Unlicense
try:
number = int(input("Enter a natural number: "))
if number < 1:
raise ValueError("A natural number is required.")
for i in range(number, 0, -1):
currentNumber = i
for j in range(currentNumber, 0, -1):
print(j, end='')
if j > 1: print(' ', end='')
print('')
except ValueError:
print("Invalid number entered.")