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
#include <iostream>
using namespace std;


void addBool(bool tab[], int a) {
	if (tab[a]) {
		tab[a] = false;
		addBool(tab, a+1);
	} else {
		tab[a] = true;
	}	
}
	
int main() {
	int amount;
	cin >> amount;
	
	int coins[amount];

	int tab_amount = 302577;
	bool tab[tab_amount];

	for (int i =0; i< tab_amount; i++) {
		tab[i] = false;
	}

	for (int i=0; i<amount; i++) {
		cin >> coins[i];
		addBool(tab, coins[i]);	
	}

	for (int i =tab_amount-1; i>=0; i--) {
		if (tab[i]) {
			cout << i;
			return 0;
		}
	}

	return 0;

}