int n;
cin >> n;
vector<int> q(n - 1);
long long sum = 0;
long long min_val = 0;
for (int i = 0; i + 1 < n; i++) {
    cin >> q[i];
    sum += q[i];
    if (sum < min_val)
        min_val = sum;
}
vector<long long> p(n);
p[0] = 1 - min_val;
forn(i, n - 1)
    p[i + 1] = p[i] + q[i];
bool ok = true;
for (int i = 0; i < n; i++)
    if (p[i] < 1 || p[i] > n)
        ok = false;
if (ok)
    ok = set<long long>(p.begin(), p.end()).size() == n;
if (ok) {
    forn(i, n)
        cout << p[i] << " ";
} else
    cout << -1 << endl;