#include <bits/stdc++.h>
using namespace std;
long long i, j, l, r, mid, p, q, k, t, n, m, a, b, c, d, ans, cnt, res, arr[1000005];
const long long mod = 999993143, mod2 = 999993469;
string s;
bool check;
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin >> n;
for (i = 2; i <= n; i += 1){
cin >> arr[i];
}
res = 0;
a = 1;
b = n;
for (i = 2; i <= n; i += 1){
res += arr[i];
if (res > 0){
b = min(b, n - res);
}
else{
a = max(a, abs(res) + 1);
}
}
if (a != b){
cout << -1 << "\n";
}
else{
cout << a << " ";
res = 0;
for (i = 2; i <= n; i += 1){
res += arr[i];
cout << a + res << " ";
}
}
}
