#include "bits/stdc++.h" using namespace std; typedef long long ll; typedef pair pii; typedef pair pll; const int INF = 1e9; const ll LINF = 1e18; template ostream& operator << (ostream& out,const pair& o){ out << "(" << o.first << "," << o.second << ")"; return out; } template ostream& operator << (ostream& out,const vector V){ for(int i = 0; i < V.size(); i++){ out << V[i]; if(i!=V.size()-1) out << " ";} return out; } template ostream& operator << (ostream& out,const vector > Mat){ for(int i = 0; i < Mat.size(); i++) { if(i != 0) out << endl; out << Mat[i];} return out; } template ostream& operator << (ostream& out,const map mp){ out << "{ "; for(auto it = mp.begin(); it != mp.end(); it++){ out << it->first << ":" << it->second; if(mp.size()-1 != distance(mp.begin(),it)) out << ", "; } out << " }"; return out; } /* 問題文============================================================ ================================================================= 解説============================================================= ================================================================ */ struct edge { int to; // 行き先 int cap; // 容量 int rev; // 逆辺 edge() {} edge(int to, int cap, int rev) :to(to), cap(cap), rev(rev) {} }; vector> G; // グラフの隣接リスト表現 vector used; // DFSですでに調べたらフラグ // fromからtoへ向かう容量capの辺をグラフに追加する void add_edge(int from, int to, int cap) { G[from].push_back(edge(to, cap, G[to].size())); G[to].push_back(edge(from, 0, G[from].size() - 1)); } // 増加パスをDFSで探す int dfs(int v, int t, int f) { if (v == t) return f; used[v] = true; for (int i = 0; i < G[v].size(); i++) { edge &e = G[v][i]; if (!used[e.to] && e.cap > 0) { int d = dfs(e.to, t, min(f, e.cap)); if (d > 0) { e.cap -= d; G[e.to][e.rev].cap += d; return d; } } } return 0; } // sからtへの最大流を求める int max_flow(int s, int t) { int flow = 0; for (;;) { fill(used.begin(), used.end(), 0); int f = dfs(s, t, INF); if (f == 0) return flow; flow += f; } } void solve(){ int N; cin >> N; vector A(N); for(auto& in:A) cin >> in; int S = 2*N,T = S+1; G.resize(2*N+2); used.resize(2*N+2); for(int i = 0; i < N;i++){ add_edge(S, i, 1); add_edge(i+N, T, 1); for(int j = 0; j < N;j++){ if(A[i] == j) continue; add_edge(i,j+N,1); } } int mflow = max_flow(S, T); if(mflow != N){ cout << -1 << endl; return; } for(int i = 0; i < N;i++){ for(auto e:G[i]){ if(e.cap == 0){ cout << e.to-N << endl; break; } } } } int main(void) { cin.tie(0); ios_base::sync_with_stdio(false); solve(); return 0; }