#include <bits/stdc++.h>
#define fo(i, d, c) for (int i = d; i <= c; i++)
#define fod(i, c, d) for (int i = c; i >= d; i--)
#define maxn 1000010
#define N 1010
#define fi first
#define se second
#define pb emplace_back
#define en cout << "\n";
#define int long long
#define inf (int)1e18
#define pii pair<int, int>
#define vii vector<pii>
#define lb(x) x & -x
#define bit(i, j) ((i >> j) & 1)
#define offbit(i, j) (i ^ (1LL << j))
#define onbit(i, j) (i | (1LL << j))
#define vi vector<int>
#define all(x) x.begin(),x.end()
template <typename T1, typename T2>
bool minimize(T1 &a, T2 b)
{
if (a > b)
{
a = b;
return true;
}
return false;
}
template <typename T1, typename T2>
bool maximize(T1 &a, T2 b)
{
if (a < b)
{
a = b;
return true;
}
return false;
}
using namespace std;
const int nsqrt = 450;
const int mod = 1e9 + 7;
int n,a[maxn],p[maxn],arr[maxn];
main()
{
#define name "TASK"
if (fopen(name ".inp", "r"))
{
freopen(name ".inp", "r", stdin);
freopen(name ".out", "w", stdout);
}
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n;
fo(i,1,n - 1)
{
cin >> a[i];
p[i] = p[i - 1] + a[i];
}
arr[1] = 1;
fo(i,1,n - 1)
{
if(p[i] <= 0) maximize(arr[1],-p[i] + 1);
else if(p[i] + arr[1] > n) return cout << -1,0;
}
fo(i,2,n) arr[i] = arr[1] + p[i - 1];
if(*max_element(arr + 1,arr + n + 1) < n) return cout << -1,0;
fo(i,1,n) cout << arr[i] << ' ';en;
}
