func_code_string: #include <bits/stdc++.h>   using namespace std;   int A[100005];   map<int, int> mymap;   int main() {     int n;     map<int, int>::iterator it;     int d;     cin >> n;     for (int i = 0; i < n; i++) {       cin >> A[i];       mymap[A[i]]++;       d = A[i];       while (mymap[d] % 2 == 0) {         mymap[d + 1]++;         mymap[d] = mymap[d] - 2;         d = d + 1;       }     }     int c = 0;     for (it = mymap.begin(); it != mymap.end(); it++) {       if (it->second == 1) c++;     }     it--;     cout << it->first - c + 1 <<   n ;     return 0;   }   