#include <bits/stdc++.h>
using namespace std;
const long long nax = 1e5 + 7;
const long long mod = 1e9 + 7;
const long long inf = numeric_limits<long long>::max();
long long n, m;
bool check(vector<long long> &vec) {
  vector<long long> freq(n + 1, 0);
  for (long long i = 0; i < n; i++) {
    if (vec[i] > n) return false;
    freq[vec[i]]++;
    if (freq[vec[i]] > 1) {
      return false;
    }
  }
  for (long long i = 0; i < n; i++) {
    if (freq[i + 1] != 1) return false;
  }
  return true;
}
void test() {
  cin >> n;
  vector<long long> vec;
  vec.push_back(0);
  long long first = 0;
  for (long long i = 1; i < n; i++) {
    long long t;
    cin >> t;
    vec.push_back(vec.back() + t);
    first = min(first, vec.back());
  }
  first = 1 - first;
  for (long long &x : vec) x += first;
  if (check(vec))
    for (long long x : vec) cout << x << ' ';
  else
    cout << -1;
}
signed main() {
  ios_base ::sync_with_stdio(false);
  cin.tie(NULL);
  long long T = 1;
  while (T--) {
    test();
    cout << "\n";
  }
  return 0;
}
