#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef vector< int > vi;
typedef vector< vi > vvi;
typedef vector< ll > vl;
typedef vector< vl > vvl;
typedef pair< int, int > pii;
typedef vector< pii > vp;
typedef vector< double > vd;
typedef vector< vd > vvd;
typedef vector< string > vs;

template< class T1, class T2 >
int upmin( T1 &x, T2 v ){
  if( x > v ){
    x = v;
    return 1;
  }
  return 0;
}

template< class T1, class T2 >
int upmax( T1 &x, T2 v ){
  if( x < v ){
    x = v;
    return 1;
  }
  return 0;
}

const int INF = 0x3f3f3f3f;

int N;
vi A;

void init(){
  cin >> N;
  A = vi( N );
  for( int i = 0; i < N; ++i )
    cin >> A[ i ];
  int diff = 0;
  for( int i = 1; i < N; ++i )
    if( A[ i ] != A[ i - 1 ] )
      diff = 1;
  if( not diff and A[ 0 ] < N )
    cout << -1 << endl, exit( 0 );
}

vi ans;

void preprocess(){
  ans = vi( N );
  for( int i = 0; i < N; ++i )
    ans[ i ] = i;
  for( ; ; random_shuffle( ans.begin(), ans.end() ) ){
    int ng = 0;
    for( int i = 0; i < N; ++i )
      ng |= ans[ i ] == A[ i ];
    if( not ng )
      break;
  }
}

void solve(){
  for( int i = 0; i < N; ++i )
    cout << ans[ i ] << endl;
}

signed main(){
  ios::sync_with_stdio( 0 );
  init();
  preprocess();
  solve();
  return 0;
}