n = int(input())
first_half_length = (n + 1) // 2
second_half_length = n - first_half_length

first_half = [str(i) for i in range(1, first_half_length + 1)]
second_half = [str(i) for i in range(1, second_half_length + 1)]

result = ''.join(first_half + second_half)
print(result)