/*

Median Strength Input Generator (IOI 2000)
Copyright (C) 2000 Paolo Boldi and Sebastiano Vigna

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


Il programma, banalmente, genera una permutazione a caso delle forze
da 1 a N.


*/


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stddef.h>
#include <time.h>

#define MAXN 1500

int forza[MAXN];


void swapint(int *a, int *b) { int t = *a; *a = *b; *b = t; }

int main(int argc, char *argv[]) {
	int i, N;

	if (argc < 2) {
		printf("Usage: %s N\n", argv[0]);
		return 0;
	}

	N = atoi(argv[1]);
	srand(clock());

	if (N % 2 == 0) {
		puts("N must be odd!");
		return 0;
	}


	for(i=0; i<N; i++) forza[i] = i+1;

	printf("%d\n", N);

	for(i=N-1; i>0; i--) 
		swapint(&forza[i], &forza[(int)((rand()/(1.0+RAND_MAX))*(i+1))]);

	for(i=0; i<N; i++) printf("%d ", forza[i]);
	printf("\n");

	return 0;
}