check1

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n;
    vector<int> a(n, 0);
    set<int> s;
    cin >> n;
    for(int i = 0; i < n; ++i){
        cin >> a[i];
    }
    vector<int> ans;
    int c;

    for(int i = 0; i < n; ++i){
        ++c;
        if(a[i] < 0 && !s.count(a[i])){
            cout << -1 << endl;
            return 0;
        }
        else if(a[i] < 0 && s.count(-a[i])){
            s.erase(-a[i]);
        }
        else if(a[i] > 0 && s.count(a[i])){
            cout << -1 << endl;
            return 0;
        }
        else if(a[i] > 0 && !s.count(a[i])){
            s.insert(a[i]);
        }
        if(s.size() == 0){
            ans.push_back(c);
            c = 0;
        }
    }
    if(s.size() > 0){
        cout << -1 << endl;
        return 0;
    }
    cout << ans.size();
    for(int i = 0; i < n; ++i){
        cout << ans[i] << " ";
    }
    cout << endl;
}