#include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<utility>
#include<cassert>
#include<complex>
#include<numeric>
using namespace std;

//#define int long long
typedef long long ll;

typedef unsigned long long ul;
typedef unsigned int ui;
constexpr ll mod = 1000000007;
const ll INF = mod * mod;
typedef pair<int, int>P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
#define all(v) (v).begin(),(v).end()
typedef pair<ll, ll> LP;
typedef long double ld;
typedef pair<ld, ld> LDP;
const ld eps = 1e-12;
const ld pi = acos(-1.0);

ll mod_pow(ll x, ll n) {
	ll res = 1;
	while (n) {
		if (n & 1)res = res * x % mod;
		x = x * x % mod; n >>= 1;
	}
	return res;
}
struct modint {
	ll n;
	modint() :n(0) { ; }
	modint(ll m) :n(m) {
		if (n >= mod)n %= mod;
		else if (n < 0)n = (n % mod + mod) % mod;
	}
	operator int() { return n; }
};
bool operator==(modint a, modint b) { return a.n == b.n; }
modint operator+=(modint& a, modint b) { a.n += b.n; if (a.n >= mod)a.n -= mod; return a; }
modint operator-=(modint& a, modint b) { a.n -= b.n; if (a.n < 0)a.n += mod; return a; }
modint operator*=(modint& a, modint b) { a.n = ((ll)a.n * b.n) % mod; return a; }
modint operator+(modint a, modint b) { return a += b; }
modint operator-(modint a, modint b) { return a -= b; }
modint operator*(modint a, modint b) { return a *= b; }
modint operator^(modint a, int n) {
	if (n == 0)return modint(1);
	modint res = (a * a) ^ (n / 2);
	if (n % 2)res = res * a;
	return res;
}

ll inv(ll a, ll p) {
	return (a == 1 ? 1 : (1 - p * inv(p % a, a)) / a + p);
}
modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); }

const int max_n = 1 << 20;
modint fact[max_n], factinv[max_n];
void init_f() {
	fact[0] = modint(1);
	for (int i = 0; i < max_n - 1; i++) {
		fact[i + 1] = fact[i] * modint(i + 1);
	}
	factinv[max_n - 1] = modint(1) / fact[max_n - 1];
	for (int i = max_n - 2; i >= 0; i--) {
		factinv[i] = factinv[i + 1] * modint(i + 1);
	}
}
modint comb(int a, int b) {
	if (a < 0 || b < 0 || a < b)return 0;
	return fact[a] * factinv[b] * factinv[a - b];
}

int k;
bool validarray(vector<int>& a) {
	int mi = mod, ma = 0;
	rep(i, a.size()) {
		if (a[i] < 0)return false;
		mi = min(mi, a[i]);
		ma = max(ma, a[i]);
	}
	return ma <= mi * 2;
}

void solve() {
	cin >> k;
	vector<int> a(k);
	rep(i, k) {
		cin >> a[i];
	}
	if (!validarray(a)) {
		cout << -1 << "\n"; return;
	}
	int sum = 0;
	rep(i, k)sum += a[i];

	int las = 0;
	vector<int> ans;
	rep(i, sum) {
		vector<bool> b(k);
		for (int j = las; j < ans.size(); j++) {
			b[ans[j]] = true;
		}
		int chk = -1;
		vector<bool> b2(k);
		rep(j, k) {
			bool valid = false;
			if (b[j])continue;
			b2 = b;
			b2[j] = true;
			for (int ex = 0; ex <= k; ex++) {
				if (las - ex < 0)break;
				if (ex > 0) {
					if (b2[ans[las - ex]])break;
					b2[ans[las - ex]] = true;
				}


				//cout << "?! " << i << " " << j <<" "<<ex<< "\n";
				vector<int> cop = a;

				cop[j]--;
				rep(x, k) {
					if (!b2[x])
					cop[x]--;
				}


				int mi = mod;
				rep(x, k)mi = min(mi, cop[x]);
				if (mi < 0)continue;

				int len = ans.size() - (las - ex);
				int fl = 0;
				bool e = false;
				rep(x, k)if (!b2[x]) {
					if (cop[x] > 2 * mi) {
						fl = len;
						cop[x]--;
						e = true;
					}
				}
				if (e)cop[j]--;
				else {
					if (cop[j] > 2 * mi) {
						fl = len;
						cop[j]--;
					}
					else {
						//cout << "hello\n";
						rep1(t, len) {
							if (cop[ans[ans.size() - t]] > 2 * mi) {
								fl = len+1 - t; break;
							}
						}
					}
				}
				rep(t, fl)cop[ans[las - ex + t]]--;
				//cout << i << " " << j << " " << ex << " " << fl << "\n";
				if (validarray(cop)) {
					valid = true; break;
				}
			}
			if (valid) {
				chk = j;
				break;
			}
		}
		//cout << chk+1 << " "<<las<<"\n";
		assert(chk >= 0);
		ans.push_back(chk);
		a[chk]--;
		if (ans.size() >= k) {
			vector<int> cnt(k, 0);
			rep(j, k) {
				cnt[ans[ans.size() - 1 - j]]++;
			}
			bool valid = true;
			rep(j, k)if (cnt[j] != 1)valid = false;
			if (valid) {
				las = ans.size();
			}
		}
	}
	rep(i, ans.size()) {
		if (i > 0)cout << " ";
		cout << ans[i]+1;
	}
	cout << "\n";
}




signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	//cout << fixed << setprecision(10);
	//init();
	//int t; cin >> t; rep(i, t)
	solve();
	return 0;
}


Measured memory_bytes: 20036