#include <bits/stdc++.h>
using namespace std;
long long mod = 1e9 + 7;
long long q[500009];
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long n;
  cin >> n;
  long long sum = 0;
  long long mini = 0;
  for (long long i = 1; i < n; i++) {
    cin >> q[i];
    sum += q[i];
    if (sum < mini) mini = sum;
  }
  bool ok = 1;
  long long p1 = 1 - mini;
  set<long long> vis;
  vector<long long> p;
  p.push_back(p1);
  vis.insert(p1);
  long long prev = p1;
  for (long long i = 1; i < n; i++) {
    long long x = prev + q[i];
    if (x < 1 or x > n or vis.count(x)) {
      ok = 0;
      break;
    }
    p.push_back(x);
    vis.insert(x);
    prev = x;
  }
  if (p[0] > n or p[0] < 1) ok = 0;
  if (!ok) {
    cout << "-1\n";
    return 0;
  }
  for (auto i : p) cout << i << " ";
  return 0;
}
