#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>  
#include <complex>
#include <queue>
#include <set>
#include <unordered_set>
#include <list>
#include <chrono>
#include <random>
#include <iostream>
#include <algorithm>
#include <cmath>
#include <string>
#include <vector>
#include <map>
#include <unordered_map>
#include <stack>
#include <iomanip>
#include <fstream>
 
using namespace std;
 
typedef long long ll;
typedef long double ld;
typedef pair<int,int> p32;
typedef pair<ll,ll> p64;
typedef pair<double,double> pdd;
typedef vector<ll> v64;
typedef vector<int> v32;
typedef vector<vector<int> > vv32;
typedef vector<vector<ll> > vv64;
typedef vector<vector<p64> > vvp64;
typedef vector<p64> vp64;
typedef vector<p32> vp32;
ll MOD = 998244353;
double eps = 1e-12;
#define forn(i,e) for(ll i = 0; i < e; i++)
#define forsn(i,s,e) for(ll i = s; i < e; i++)
#define rforn(i,s) for(ll i = s; i >= 0; i--)
#define rforsn(i,s,e) for(ll i = s; i >= e; i--)
#define ln "\n"
#define dbg(x) cout<<#x<<" = "<<x<<ln
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define INF 2e18
#define fast_cin() ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((ll)(x).size())
 
ll mpow(ll a, ll b){
	if(a==0) return 0;
	if(b==0) return 1;
	ll t1 = mpow(a,b/2);
	t1 *= t1;
	t1 %= MOD;
	if(b%2) t1 *= a;
	t1 %= MOD;
	return t1;
}
 
ll mpow(ll a, ll b, ll p){
	if(a==0) return 0;
	if(b==0) return 1;
	ll t1 = mpow(a,b/2,p);
	t1 *= t1;
	t1 %= p;
	if(b%2) t1 *= a;
	t1 %= p;
	return t1;
}
 
ll modinverse(ll a, ll m){
	ll m0 = m; 
    ll y = 0, x = 1; 
    if (m == 1) return 0; 
    while (a > 1){
        ll q = a / m; 
        ll t = m; 
        m = a % m, a = t; 
        t = y; 
        y = x - q * y; 
        x = t; 
    }
    if (x < 0) x += m0; 
    return x; 
}

mt19937_64 mt(chrono::steady_clock::now().time_since_epoch().count());
 
ll range(ll l, ll r){
	return l + mt()%(r-l+1);
}
 
ll rev(ll v){
	return mpow(v,MOD-2);
}

void solve(){
	ll n;
	cin >> n;
	ll a[n];
	ll mn = 1000;
	ll mx = 0;
	ll mx1 = 0;
	ll l=0;
	forn(i,n){
		cin >> a[i];
		l+=a[i];
		mn = min(mn,a[i]);
		mx = max(mx,a[i]);
		if(i) mx1 = max(mx1,a[i]);
	}
	if(mx>2*mn){
		cout << -1 << ln;
		return;
	}
	bool pr[n];
	forn(i,n) pr[i]=1;
	ll ans[l];
	ll c = 0;
	bool cmp[n];
	forn(i,n) cmp[i]=0;
	v64 vec;
	forn(i,l){
		// cout << i << ln;
		ll val=-1;
		forn(j,n){
			if(pr[j]){
				// cout << j << " " << j << ln;
				bool bo = 0;
				v64 temp;
				forn(k,n){
					if(a[k]>(2*a[j]-1)){
						bo=1;
						break;
					}
					else if(a[k]==(2*a[j]-1)){
						temp.pb(k);
					}
				}
				if(!bo){
					val = j;
					if(sz(temp)){
						c = sz(temp);
						for(auto it : temp) cmp[it]=1;
					}
					break;
				}
			}
		}
		assert(val!=-1);
		a[val]--;
		ans[i]=val;
		if(c) vec.pb(val);
		if(cmp[val]){
			c--;
			cmp[val]=0;
			if(c==0) vec.clear();
		}
		// cout << c << ln;
		cout << val+1 << " ";
		pr[val]=0;
		if(i>=n-1){
			bool pr1[n];
			forn(i,n) pr1[i]=0;
			bool bo = 1;
			forsn(j,i-n+1,i+1){
				if(pr1[ans[j]]){
					bo=0;
					break;
				}
				pr1[ans[j]]=1;
			}
			if(bo){
				forn(j,n) pr[j]=1;
				for(auto it : vec) pr[it]=0;
			}
		}
	}
	cout << ln;
}
 
int main()
{
	fast_cin();
    ll t=1;
    // cin >> t;
    forn(i,t) {
    	// cout << "Case #" << i+1 << ": ";
    	solve();
    }
    return 0;
}

Measured memory_bytes: 3660