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

const int N = 1e5+10;

int a[N],p[N],t,n,v[N];

void init(){
	memset(p,0,sizeof(p));
	memset(v,0,sizeof(v));
}

int main(){
	freopen("permutation.in","r",stdin);
	freopen("permutation.out","w",stdout);
	scanf("%d",&t);
	while(t--){
		scanf("%d",&n);
		init();
		for(int i=1;i<n;i++){
			scanf("%d",&a[i]);
			v[a[i]]++; 
		}
		int flag=0;
		for(int i=2;i<=n;i++){
			if(v[i]>1)flag=1;
		}
		if(a[n-1]!=1){
			printf("-1\n");
		}else if(v[1]>2){
			printf("-1\n");
		}else if(flag){
			printf("-1\n");
		}else if(v[1]==1){
			p[1]=1;
			int op;
			for(int j=1;j<=n;j++){
				if(v[j]==0)op=j;
			}
			p[n]=op;
			int l=2,r=n-1,idx=1;
			while(l<r){
				if(p[l-1]>p[r+1]){
					p[l++]=a[idx];
				}else{
					p[r--]=a[idx];
				}
				idx++;
			}
			if(!p[l])p[l]=a[idx];
			for(int i=1;i<=n;i++){
				printf("%d ",p[i]);
			}
			printf("\n");
		}else if(v[1]==2){
			int boo=1;
//			cout<<endl;
			for(int j=1;j<=n;j++){
//				cout<<v[j]<<" ";
				if(v[j]==0&&boo){
					p[1]=j;
					boo=0; 
				}else if(v[j]==0){
					p[n]=j;
				}
			}
//			cout<<endl;
			if(p[1]>p[n])swap(p[1],p[n]);
//			cout<<p[1]<<' '<<p[n]<<"RRR"<<endl;
//			cout<<v[p[1]]<<" "<<v[p[n]]<<"TTT"<<endl;
			int l=2,r=n-1,idx=1;
			while(l<r){
				if(p[l-1]>p[r+1]){
					p[l++]=a[idx];
				}else{
					p[r--]=a[idx];
				}
				idx++;
			}
			p[l]=a[idx];
			for(int i=1;i<=n;i++){
				printf("%d ",p[i]);
			}
			printf("\n");
		}else if(v[1]==0){
			printf("-1\n");
		}
	}
	return 0;
}