#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
using namespace std;

#define rep(i,n) for(int i=0;i<n;i++)
#define ll long long

int n;
vector<int> seat,a;

int main() {

	cin >> n;
	seat.resize(n);
	a.resize(n);
	rep(i, n) {
		cin >> a[i];
		seat[i] = i;
	}
	
	bool flag = true, flag2 = true;;
	while (flag && flag2) {
		rep(i,n) {
			if (a[i] == seat[i]) {
				bool fin = true;
				rep(j, n) {
					if (a[j] != seat[i]) {
						cout << 1 << endl;
						swap(seat[i], seat[j]);
						break;
					}
					if (j == n - 1) {
						cout << -1 << endl;
						flag2 = false;
					}
				}
				flag = false;
				rep(j, n) {
					if (a[j] == seat[j]) flag = true;
				}
				break;
			}

		}
	}

	if (flag2) {
		rep(i, n) {
			cout << seat[i] << endl;
		}
	}
	return 0;
}