include

include

include

using namespace std;

int main()
{
vector<int> res;
int n;
while(cin >> n)
{
//输入n个数
while(n --){
int num;
cin >> num;
res.push_back(num);
}
//假如n == 1
if(res.size() == 1) cout << res[0] << endl;
//对n个数进行排序，O(nlogn)
sort(res.begin(),res.end());
//双指针方法，j指向i的下一个数，假如res[i] == res[j],j向后移动一位
for(int i = 0,j = i + 1;i < res.size() && j < res.size();i ++)
{
//假如
while(res[i] == res[j]){
j ++;
}
//因为j ++了
i = j - 1;
cout << res[i] << endl;</int>

    }
    res.clear();
}
return 0;

}