#include <bits/stdc++.h>
using namespace std;
#define oo 1e15
#define fi first
#define se second
#define sp(iiii) setprecision(iiii)
#define IO ios_base::sync_with_stdio(false); cin.tie(0)
#define ms(aaaa,xxxx) memset(aaaa,xxxx,sizeof(aaaa))
#define cntbit(xxxx) __builtin_popcount(xxxx)
#define getbit(xxxx,aaaa) ((xxxx>>(aaaa-1))&1)
typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<pair<int,int>,int> piii;
typedef pair<long long,long long> pll;
typedef pair<pair<long long,long long>,long long> plll;
typedef pair<pair<long long,long long>,pair<long long,long long>> pllll;
typedef pair<pair<long long,long long>,bool> pllb;
const ll base=361;
const ll mod=998244353;
const ld eps=1e-5;
const ll maxn=1e6;
ll n,l,r,p,a[500009],i;
int main(){
IO;
cin>>n;
l=1;
r=1;
p=1;
for (i=1;i<n;i++) {
cin>>a[i];
p+=a[i];
l=min(l,p);
r=max(r,p);
}
p=1;
//cout<<l<<' '<<r<<'\n';
while (l<1) {
l++;
r++;
p++;
}
if (r!=n) {
cout<<-1<<'\n';
return 0;
}
else {
cout<<p<<' ';
for (i=1;i<n;i++) {
p+=a[i];
cout<<p<<' ';
}
}
}
