snaily_oddbit.cpp

#include<iostream>
#include<bitset>

#define MAXN 100000
using namespace std;

int main()
{
    bitset<MAXN> b;
    unsigned long n, in, i;
    cin>>n;
    i=n;
    while(i--)
    {
        cin>>in;
        b.flip(--in);
    }
    i=n;
    while(i--)
    {
        if(b.test(i))cout<<(i+1)<<endl;
    }
    return 0;
}