#include<bits/stdc++.h>
using namespace std;
int h[100005];
int v[100005];
int a[100005];
bool in[100005];
void solve(){
	memset(v,0,sizeof v);
	memset(in,0,sizeof in);memset(a,0,sizeof a);memset(h,0,sizeof h);
	int n;cin>>n;
	for(int i=1;i<=n-1;i++){
		cin>>h[i];
		v[h[i]]++;
	}
	if(h[n-1]!=1){
		cout<<-1<<endl;return;
	}
	int x1=0,x2=0;
	for(int i=1;i<=n;i++){
		if(v[i]==0){
			if(x1)x2=i;
			else x1=i;
		}if(v[i]>1&&i>1||v[i]>2){
			cout<<-1<<endl;return;
		}
	}
	if(x1>x2)swap(x1,x2);
	if(x1==0)x1=1;
	int l=1,r=n;
	a[l]=x1;a[r]=x2;
	in[x1]=in[x2]=1;
	int nw=1;
	for(int i=3;i<=n;i++){
		if(a[l]>a[r]){
			while(in[h[nw]])nw++;
			a[++l]=h[nw];
			in[h[nw]]=1;
		}else{
			while(in[h[nw]])nw++;
			a[--r]=h[nw];
			in[h[nw]]=1;
		}
	}
	for(int i=1;i<=n;i++)
	{
		printf("%d ",a[i]);
	}
	printf("\n");
}
int main()
{
	freopen("permutation.in","r",stdin);
    freopen("permutation.out","w",stdout);
	int t;
	scanf("%d",&t);
	while(t--) solve(); 
	return 0;
}