#include <bits/stdc++.h>   using namespace std;   int main() {     int n, i = 0;     cin >> n;     long long a;     vector<long long> vc;     while (n--) {       cin >> a;       vc.push_back(a);     }     sort(vc.begin(), vc.end());     i = vc.size();     long long ans = vc[i - 1];     for (int j = i - 2; j >= 0; j--) {       if (vc[j] >= vc[j + 1]) {         vc[j] = vc[j + 1] - 1;       }       if (vc[j] > 0) ans += vc[j];     }     cout << ans << endl;   }   