Codeforces Round #136 (Div. 2) / 221A Little Elephant and Function (数学)

A. Little Elephant and Function

http://codeforces.com/problemset/problem/221/A

time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

The Little Elephant enjoys recursive functions.

This time he enjoys the sorting function. Let a is a permutation of an integers from 1 to n, inclusive, and a_i denotes the i-th element of the permutation. The Little Elephant's recursive function f(x), that sorts the first x permutation's elements, works as follows:

• If x = 1, exit the function.
• Otherwise, call f(x - 1), and then make swap(a_x - 1, a_x) (swap the x-th and (x - 1)-th elements of a).

The Little Elephant's teacher believes that this function does not work correctly. But that-be do not get an F, the Little Elephant wants to show the performance of its function. Help him, find a permutation of numbers from 1 to n, such that after performing the Little Elephant's function (that is call f(n)), the permutation will be sorted in ascending order.

Input

A single line contains integer n (1 ≤ n ≤ 1000) — the size of permutation.

Output

In a single line print n distinct integers from 1 to n — the required permutation. Numbers in a line should be separated by spaces.

It is guaranteed that the answer exists.

Sample test(s)

input

1

output

1 

input

2

output

2 1 

从后往前反推+找规律。

完整代码：

/*30ms,0KB*/

#include<cstdio>

int main(void)
{
	int n;
	scanf("%d", &n);
	if (n == 1)
		putchar('1');
	else
	{
	    printf("%d", n);
		for (int i = 1; i < n; ++i)
			printf(" %d", i);
	}
	return 0;
}