1739B.cpp

#include <bits/stdc++.h>
using namespace std;

int main() {
    int t;
    cin >> t;
    while (t--) {
        int n;
        cin >> n;
        vector<int> d(n);
        for (int i = 0; i < n; i++) cin >> d[i];

        vector<int> ans;
        ans.push_back(d[0]);
        bool possible = true;

        for (int i = 1; i < n; i++) {
            if (ans[i - 1] - d[i] < 0) {
                ans.push_back(ans[i - 1] + d[i]);
            } else if (ans[i - 1] - d[i] >= 0 && d[i] == 0) {
                ans.push_back(ans[i - 1]); 
            } else {
                cout << -1 << endl;
                possible = false;
                break;
            }
        }

        if (possible) {
            for (int val : ans) cout << val << " ";
            cout << endl;
        }
    }

    return 0;
}