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
#include <iostream>

int main()
{
    std::ios::sync_with_stdio(false);
    const int arrSize = 201718 + 1;
    int* powArr = new int[arrSize]();
    
    int n, a_i;
    std::cin>>n;
    for(int i=0; i<n; ++i){
        std::cin>>a_i;
        ++powArr[a_i];
    }
    
    int maxPow = 0;
    for(int a_i=0; a_i<arrSize-1; ++a_i){
        powArr[a_i+1] += powArr[a_i]/2;
        if(powArr[a_i+1]) maxPow = a_i + 1;
    }
    
    std::cout << maxPow << std::endl;
    
    delete[] powArr;
}