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
34
35
36
37
38
39
40
41
42
43
44
45
46
47
#include <bits/stdc++.h>
using namespace std;

typedef long long LL;
typedef long double LD;
typedef unsigned long long ULL;
typedef vector<int> VI;
typedef set<int> SI;
typedef pair<int, int> PII;
typedef vector<pair<int, int> > VPII;

#define FOR(i, b, e) for(int i = b; i <= e; i++)
#define FORD(i, b, e) for(int i = b; i >= e; i--)
#define ALL(c) (c).begin(), (c).end()
#define SIZE(x) ((int)(x).size())
#define VAR(v, n) auto v = (n)
#define FOREACH(i, c) for(VAR(i, (c).begin()); i != (c).end(); ++i)

#define MP make_pair
#define PB push_back
#define ST first
#define ND second
#define GGL(x) "Case #" << x << ": "


/*************************** END OF TEMPLATE ***************************/

int tab[201739];

int main()
{
    int n;
    scanf("%d", &n);
    int curr;
    FOR(i, 0, n-1){
        scanf("%d", &curr);
        tab[curr]++;
    }
    int res = 0;
    FOR(i, 1, 201739){
        tab[i] += tab[i-1]/2;
        if(tab[i] > 0)
            res = i;
    }
    printf("%d\n", res);
    return 0;
}