#include <bits/stdc++.h>

using namespace std;

namespace {

    typedef double real;
    typedef long long ll;

    template<class T> ostream& operator<<(ostream& os, const vector<T>& vs) {
        for (auto& v : vs) {
            os << v << endl;
        }
        return os;
    }
    template<class T> istream& operator>>(istream& is, vector<T>& vs) {
        for (auto it = vs.begin(); it != vs.end(); it++) is >> *it;
        return is;
    }

    int N;
    vector<int> A;
    void input() {
        cin >> N;
        A.clear(); A.resize(N); cin >> A;
    }

    void solve() {
        vector<bool> ng_exist(N, false);
        vector<vector<int>> ng_id(N);
        for (int i = 0; i < N; i++) {
            ng_id[A[i]].push_back(i);
            ng_exist[A[i]] = true;
        }
        vector<int> wildcard;
        for (int i = 0; i < N; i++) if (not ng_exist[i]) wildcard.push_back(i);

        //cout << "ng_id: " << ng_id << endl;
        //cout << "wildcard: " << wildcard << endl;

        vector<int> id(N, -1);
        for (int i = 0; i < N; i++) {
            if (ng_id[i].empty()) continue;
            int x = ng_id[i][0];
            int next = (i + 1) % N;
            while (ng_id[next].empty()) next = (next + 1) % N;
            if (i == next) {
                cout << -1 << endl;
                return;
            }
            id[x] = next;
            for (int j = 1; j < ng_id[i].size(); j++) {
                id[ng_id[i][j]] = wildcard.back();
                wildcard.pop_back();
            }
        }
        cout << id << endl;
    }
}

int main() {
    input(); solve();
    return 0;
}