#include <bits/stdc++.h>
using namespace std;
long long a[300005];
long long c[300005] = {0};
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int n;
  cin >> n;
  int i;
  for (i = 1; i <= n - 1; i++) cin >> a[i];
  long long m = 0;
  long long r = 0;
  for (i = 1; i <= n - 1; i++) {
    r += a[i];
    m = min(m, r);
  }
  m = abs(m) + 1;
  long long y = m;
  if (m > n || c[m]) {
    cout << -1;
    return 0;
  }
  c[m] = 1;
  for (i = 1; i <= n - 1; i++) {
    m += a[i];
    if (m > n || c[m]) {
      cout << -1;
      return 0;
    }
    c[m] = 1;
  }
  cout << y << " ";
  for (i = 1; i <= n - 1; i++) {
    y += a[i];
    cout << y << " ";
  }
  return 0;
}
