func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(false);     int n, ans = 0, i, temp;     vector<int> a;     cin >> n;     for (i = 0; i < n; i++) {       cin >> temp;       a.push_back(temp);     }     sort(a.begin(), a.end());     for (i = 0; i < n; i = i + 2) {       if (a[i] != a[i + 1]) {         ans += (a[i + 1] - a[i]);       }     }     cout << ans << endl;     return 0;   }   