func_code_string: #include <bits/stdc++.h>   using namespace std;   int M = 1000000007;   long long n, m;   void solve() {}   void test() {     long long n;     cin >> n;     vector<int> a(n);     int count[101] = {         0,     };     for (long long i = 0; i < n; i++) {       cin >> a[i];       count[a[i]]++;     }     bool flag = 1;     int ans = 0;     for (long long i = 0; i < 101; i++) {       if (count[i] == 0 && flag) {         cout << 2 * i << endl;         return;       }       if (count[i] == 1 && flag) {         ans += i;         flag = 0;       }       if (count[i] == 0 && !flag) {         ans += i;         cout << ans << endl;         return;       }     }   }   int main() {     long long t;     cin >> t;     while (t--) test();     return 0;   }   