[C++] 백준 5597번 : 과제 안 내신 분..?

https://www.acmicpc.net/problem/5597

#include <iostream>

using namespace std;

int main() {

int ary[30] = { 0, };

int n;

for (int i = 0; i < 28; i++)

{

cin >> n;

ary[n - 1] = 1;

}

for (int i = 0; i < 30; i++)

if (!ary[i])

cout << i + 1 << "\n";

}