func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int t;     cin >> t;     while (t--) {       int n;       cin >> n;       int arr[n];       for (int i = 0; i < n; i++) {         cin >> arr[i];       }       int res[101] = {0};       for (int i = 0; i < n; i++) {         res[arr[i]]++;       }       int cnt[101] = {0};       for (int i = 0; i < 101; i++) {         if (res[i] >= 1) {           res[i]--;           cnt[i]++;         }       }       int f, s;       for (int i = 0; i < 101; i++) {         if (res[i] == 0) {           f = i;           break;         }       }       for (int i = 0; i < 101; i++) {         if (cnt[i] == 0) {           s = i;           break;         }       }       cout << f + s <<   n ;     }   }   