1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
#include <iostream>
#include<sstream>
#include<fstream>
#include<algorithm>
#include <vector>
#include <stdexcept>
#define ll long long
using namespace std;


int A[300000];

int main() {
    std::ios::sync_with_stdio(false);
    istream& my_in = cin;
    int n;
    cin >>n;
    for(int i=0;i<n;i++){
        int x;
        cin >> x;
        A[x]++;
    }
    int res =0;
    for(int i=0;i<300000;i++) {
        A[i+1]+=A[i]/2;
        if(A[i]>0)res = i;
    }
    cout << res<<endl;
    return 0;
}