#include "bits/stdc++.h"
using namespace std;
#define ll long long int
bool chk(vector<ll> v) {
set<ll> st;
for (ll i = 0; i < (ll) (v.size()) - 1; i++) {
st.insert(v[i] - v[i + 1]);
}
return (st.size() == 1 || st.size() == 0);
}
int main(int argc, char const *argv[]) {
ios::sync_with_stdio(false);
cin.tie(nullptr);
ll n, k;
cin >> n;
vector<ll> v;
for (ll i = 0; i < n; i++) cin >> k, v.push_back(k);
sort(v.begin(), v.end());
for (ll i = 0; i < (1 << n); i++) {
vector<ll> ano;
map<ll, ll> mp;
for (ll j = 0; j < n; j++) {
if (i & (1 << j)) ano.push_back(v[j]), mp[j]++;
}
vector<ll> anoo;
for (ll j = 0; j < n; j++) if (!mp[j]) anoo.push_back(v[j]);
if (anoo.size() && ano.size() && chk(ano) && chk(anoo)) {
cout << ano.size() << endl;
for (ll j : ano) cout << j << " ";
cout << endl;
cout << anoo.size() << endl;
for (ll j : anoo) cout << j << " ";
cout << endl;
return 0;
}
}
cout << -1 << endl;
return 0;
}
