#include<bits/stdc++.h>
#define For(i,a,b) for(register int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(register int i=(a);i>=(b);--i)
using namespace std;
inline int read()
{
	char c=getchar();int x=0;bool f=0;
	for(;!isdigit(c);c=getchar())f^=!(c^45);
	for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
	if(f)x=-x;return x;
}
 
#define mod 1000000007
struct modint{
	int x;
	modint(int o=0){x=o;}
	modint &operator = (int o){return x=o,*this;}
	modint &operator +=(modint o){return x=x+o.x>=mod?x+o.x-mod:x+o.x,*this;}
	modint &operator -=(modint o){return x=x-o.x<0?x-o.x+mod:x-o.x,*this;}
	modint &operator *=(modint o){return x=1ll*x*o.x%mod,*this;}
	modint &operator ^=(int b){
		modint a=*this,c=1;
		for(;b;b>>=1,a*=a)if(b&1)c*=a;
		return x=c.x,*this;
	}
	modint &operator /=(modint o){return *this *=o^=mod-2;}
	friend modint operator +(modint a,modint b){return a+=b;}
	friend modint operator -(modint a,modint b){return a-=b;}
	friend modint operator *(modint a,modint b){return a*=b;}
	friend modint operator /(modint a,modint b){return a/=b;}
	friend modint operator ^(modint a,int b){return a^=b;}
	friend bool operator ==(modint a,int b){return a.x==b;}
	friend bool operator !=(modint a,int b){return a.x!=b;}
	bool operator ! () {return !x;}
	modint operator - () {return x?mod-x:0;}
	bool operator <(const modint&b)const{return x<b.x;}
};
inline modint qpow(modint x,int y){return x^y;}

vector<modint> fac,ifac,iv;
inline void initC(int n)
{
	if(iv.empty())fac=ifac=iv=vector<modint>(2,1);
	int m=iv.size(); ++n;
	if(m>=n)return;
	iv.resize(n),fac.resize(n),ifac.resize(n);
	For(i,m,n-1){
		iv[i]=iv[mod%i]*(mod-mod/i);
		fac[i]=fac[i-1]*i,ifac[i]=ifac[i-1]*iv[i];
	}
}
inline modint C(int n,int m){
	if(m<0||n<m)return 0;
	return initC(n),fac[n]*ifac[m]*ifac[n-m];
}
inline modint sign(int n){return (n&1)?(mod-1):(1);}

#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;

#define maxn 200005
#define inf 0x3f3f3f3f

int n,a[maxn],vis[maxn];
set<int>s;

bool chk(int x,int y){
	if(x<-n||y<-n)return 1;
	if(abs(x-y)==1)return 0;
	return 1;
}

int num[maxn],len,p[maxn],pos[maxn],orz;

void work(){
	For(i,1,len){
		a[pos[i]]=num[p[i]];
	}
	For(i,1,len){
		int u=pos[i];
		if(!chk(a[u-1],a[u])||!chk(a[u+1],a[u]))return;
	}
	For(i,1,n){
		cout<<a[i]<<" ";
	}
	exit(0);
}

signed main()
{
	n=read();
	For(i,1,n)a[i]=read();
	For(i,1,n)if(a[i]!=-1)vis[a[i]]=1;
	For(i,1,n)if(!vis[i])s.insert(i);
	a[0]=a[n+1]=-inf;
	For(i,1,n)if(a[i]==-1){
		if(s.size()>6){
			auto it=s.begin();
			while(!chk(a[i-1],*it) || !chk(a[i+1],*it))++it;
			a[i]=*it,s.erase(it);
		}else break;
	}
	while(s.size())num[++len]=(*s.begin()),s.erase(s.begin());
	For(i,1,n)if(a[i]==-1)pos[++orz]=i;
	assert(len==orz);
	For(i,1,len)p[i]=i;
	do{
		work();
	}while(next_permutation(p+1,p+len+1));
	puts("-1");
	return 0;
}