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
31
32
33
#include <bits/stdc++.h>
//#define int long long
#define st first
#define nd second
#define mp(a, b) make_pair(a, b)
#define pb push_back
#define mt make_tuple
#define e(a, b) get<b>(a)
using namespace std;
int tbl[2000000];
int32_t main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int n;
	cin>>n;
	int a;
	for (int i=0; i<n; i++)
	{
		cin>>a;
		tbl[a]++;
	}
	a=0;
	for (int i=0; i<2000000; i++)
	{
		if (tbl[i]!=0)
			a=i;
		tbl[i+1]+=tbl[i]/2;
		tbl[i]%=2;
	}
	cout<<a;
	return 0;
}